Boat is given to you to cross the river, not to start perfecting the boat and become a sailor. Spiritual Journey is not a pursuit of attaining perfection in any Kosha (Body/Sheath). Don't be stuck at one or more Koshas.
Spiritual Journey for Moksha or Nirvana is not about -
1. Learning all the Asanas and perfecting many Yoga Postures. Making those Asanas the ultimate goal of your life. Fixing your eating, breathing, sleeping, cleaning and life to an extent that it seems your Physical Body is "the most" important thing for you. In other words, it is not about perfecting Annamaya Kosha.
2. Learning all possible Kriyas of the Kriya Yoga, all about 72,000 Nadis and all 114 Chakras and opening and balancing each one of them. The journey is not about raising Kundalini to play with the Powers of Astral Body and open chakras. It is not about doing Bhakti of Shakti for the sake of visions & powers. In other words, it is not about perfecting Pranamaya Kosha.
3. The spiritual journey is not about attaining 100% purity of emotions and 100% balance of Mind. Yes, "I-Thought" needs to die, but it doesn't mean you become all Love, Bliss & Peace before this happens. Yes, you will be using your emotions as tools later on, but that doesn't mean you focus too much on the Tools. You will have to wear your Ego again as a Costume after Self-Realization, but that doesn't mean you focus way too much on perfecting it because it's like spending too much time on your costume than the Real Thing. It is also not about fixing each and every Karma of yours, because Karma is nothing but the output of tools & costume. It is also not about surfing the waves of sweet-pleasant emotions of Bhakti at all times, because in the end whether it is a Bhakta or Shakta or a Bhogi, the Experiencer will be dead. In other words, it is not about perfecting Manomaya Kosha.
4. The spiritual journey is not about attaining all 8 to 18 Siddhis/Psychic Powers. They are not the prerequisite for Self-Realization or Moksha. If you develop and strengthen this Vigyanmaya Kosha a lot, then you stand a very heavy chance of creating mountain-load of Karma. This is the worst kind of attachment/trap. It is also not about gathering the knowledge about ALL possible sacred scriptures, texts, books, shlokas, mantras, Tantras, Yantras and all.
5. Spiritual Journey is also not about enjoying the bliss through Anandamaya Kosha for as many times as possible, as long as possible. The more perfection you attain the more attachment you are creating for yourself, which will be very hard to break later on and will actually defeat the purpose of Spiritual Journey. So you see, the perfection of all these Koshas is not the "aim". Aim or Goal of the spiritual journey is Moksha! You are given all these Koshas as a medium to reveal your True Self, to be Self-Realized. They are like a boat being given to you to cross the river.
Imagine you intend to cross a river and you got a boat. But instead of crossing the river, you took the boat and started carving it, decorating it, perfecting it and then practising a lot in the river to sail it this way, that way and upside down and in few years you became a Boat Expert and/or Best Sailor. Means you did everything except crossing that goddamn river and be on the other side!
How to know when it is too much?
Very simple. When you start liking and enjoying your Sadhana! When your focus & attention starts going more on the pleasure, pleasantness, joy/bliss, love (sweetness of emotions) instead of your Vasanas, Karmic Lessons. Do not forget that each Sadhana/Spiritual Practice was given to you to fulfil a purpose, if it's done, leave the Sadhana. No need to keep doing it. If you don't know the purpose or expiry conditions of a spiritual practice, ask your Guru, Teacher who gave you that Sadhana.
You might have been taught "to do the Sadhana". But you also need to know "when to stop doing it". When to leave it.
There comes a time on Spiritual Journey when the only Sadhana that is needed is "not doing any Sadhana", Non-Doing, Dissolving the Doer, Surrendering!!!
What if you have got an attachment with one or more Kosha & you are trapped?
Well, now your Guru/Teacher have to be tricky with you :-)
Many Gurus will do this - They will give you Sadhana & Teachings to strengthen another Kosha in you and then you will automatically leave the attachment of the other Kosha. For example, if someone is way head over heels about their beauty & physical appeal, then these type of Gurus will help their students develop & strengthen their mind or energy or something else so much that their beauty to them feels like something of no great importance. This is a "replacement of trap".
Means earlier your trap was made up of Ebony and now it is made up of Sandal Wood. Many Gurus teach you to replace your negative thoughts with a positive one. Replace one thing with another.
Well, it may look like a solution, but it never is.
Real Gurus (Outer Sadh-Guru or Inner Guru - Trikuti) will "show" you, your own attachment by purifying your Intellect/Buddhi step by step. So that you start "seeing attachments/traps/hooks/cage". They give you Shakti to break the attachments. Once you start seeing them for what they really are and how they hold you back, you will leave them and also will never get caught in another one. Those who give you just Shakti but not Buddhi/Intellect to see the traps, then you may get into another one. So awakening/purifying your Buddhi is a very important step.
This means all attachments/traps exists only until Buddhi/Intellect is not purified and Light of Wisdom is off. Once that Light is turned ON, everything appears the way it is. Attachments and Traps do not glitter like gold anymore, instead, are seen as such, a cage of thorns.
One thing to remember here is that all that you can ever "experience" or "know" or "be" through any or all of your Kosha(s), is so limited in comparison to the #INFINITUDE that you will be once you break the traps of any and all Koshas. So, trust your own ability to break the barriers of all Koshas.
Through your spiritual practices, you are becoming more and more Conscious, Aware of your different Koshas and knowing more and more about them not to fall in love with them, not to make them your home, but to break the boundary that they impose on you.
Many Gurus can teach you Karma Yoga, Kriya Yoga, Bhakti Yoga. But Jnana (Gyan) Yoga can be taught effectively only by a Self-Realized Guru. In other words, only a Self-Realized Guru or Inner Guru Chakra - Trikuti can purify your Buddhi/Intellect. Many Gurus and people can touch/purify your Koshas, Shakti (Energy, Kundalini), Mind, Emotions, Power Center, Chakras and everything else, but only a Self-Realized Guru or Trikuti can teach you the purification of your Buddhi/Intellect. Buddhi/Intellect is that which "veils the truth". The truth of who we really are. It veils the "SELF". That veil is what we call Maya/Ignorance. After purification Buddhi/Intellect "transcends" and becomes MAHAT - Cosmic Intelligence and you become the Cosmic Being and finally you even break that boundary and just "be", only "SELF".
Not all Self-Realized ones can do Hatha Yoga and all Asanas/Postures perfectly. Their physical body, habits, eating, sleeping, living, lifestyle is 100% Conscious, but may not be perfect. In other words, if someone's Annamaya Kosha is not perfect then that doesn't mean they are not Self-Realized. Yet in other words, the perfection of Annamaya Kosha is not the prerequisite for Self-Realization.
Not all Self-Realized ones are adept in Kriya Yoga and the knowledge of Mudras, Kundalini, Chakras, Pranayama etc. Yes, technically Kundalini awakens, and their Pranamaya Kosha is 100% Conscious, but it is not necessary that the one who is Self-Realized has done some special Kundalini Sadhana and he/she may have blockages in certain Nadis/Chakras. Means perfection of Pranamaya Kosha is not the prerequisite for Self-Realization. In other words, if a Self-Realized one doesn't talk/teach/preach about Shakti/Kundalini and/or if they have blocked Nadis/Chakras, then that doesn't mean they are not Self-Realized.
Not all Self-Realized ones are great in releasing Vasanas through Mental/Emotional Body, means Manomaya Kosha. And their emotional tools and ego costume may be really faulty, they may not be worldly-wise at all, they will feel and cry in love & pain of the entire cosmos, as their Manomaya Kosha is 100% Conscious. Just because they are in tears easily and make bad worldly choices doesn't mean they are not Self-Realized. The perfection of Manomaya Kosha is not the prerequisite for Self-Realization.
Not all Self-Realized ones are Mystics as their Vigyanamaya Kosha may not have attained the height of perfection, it is 100% Conscious though. Having or not having Siddhis/Powers in no way is a measure for Self-Realization or the greatness of the Self-Realized one. Because the perfection of Vigyanmaya Kosha is not the prerequisite for Self-Realization. Everything around them works through the power of SELF and the power is applied wherever it is needed.
Anandamaya Kosha is merged with the Cosmic Anandamaya Kosha, Supreme Consciousness, SELF. Hence Sat-Chit-Ananda is the very nature of a Self-Realized one, but may not be reflected as such if the Manomaya Kosha is not that developed or expressive, or may be reflected through their Physical body as a glow/light or through their Aura from Pranamaya Kosha. So not all Self-Realized ones may instantly, easily look like sailing in Love, Peace, Bliss. They are though, but it's just that it doesn't flow down to the lowest level to be visible through their Koshas. Some Self-Realized ones look crazy, furious instead. Their Anandamaya Kosha is 100% Conscious. But the display of Peace, Bliss, Love through Anandamaya Kosha or any other Kosha is not the criteria or prerequisite for Self-Realization.
Not all Self-Realized ones have perfected all aspects of TRIKUTI (Guru Chakra) & VOID (Space of all previous Gurus & Wisdom) and hence may not become Guru to teach/preach the humanity. They may stay in Samadhi forever and live life in Sahaja but may not become a Guru for anyone or everyone. Mastering all these and/or becoming Guru is also not a prerequisite for Self-Realization.
Becoming 100% Conscious of your Koshas and your whole existence is different than strengthening their abilities, powers. Being 100% Conscious is the requirement for Self-Realization. Being 100% powerful and perfect is NOT the criteria for Self-Realization. Self-Realized ones are 100% Conscious, they are not 100% Perfect.
When you become Aware/Conscious of your Koshas, you break the boundaries, but if you perfect your Koshas then you fall in love with them.
One thing that is the CRITERIA & PREREQUISITE, as well as a COMMON ground for every Self-Realized one, is - SELF-ILLUMINED BUDDHI/INTELLECT. In other words 100% Pure, Sattvik Buddhi. Buddhi is what makes one Buddha.