Why does sAdhanA seem to be taking so long to bear fruit?

Aim for cessation of thought but the apparent passage of time between this resolve and its permanence may seem long.

In the Bhagavad GItA 6.25 SrI KRShNa says

शनै: शनैरुपरमेद् बुद्ध्या धृतिर्गृहीतया ।

अअत्मसंस्थं मन: कृत्वा न किञ्चिदपि चिन्तयेत् ॥

Slowly, slowly one must withdraw by degrees, by the buddhi held with firmness.

Having established the mind in the Self, he should not think of anything else.

My father used to draw the analogy of samsAra with a silk dress thrown on a brambly bush. It can only be withdrawn gently and with great care.

Purusha is the silk dress and the brambles are the guNas.

Dare I disturb the Universe? as T. S. Eliot wrote.

Yet if the "I" dissolves, then everything is ok. 

SUtradhAra (the support of the string)

SUtradhAra, the support of the string, is the power of sequencing not only lives but thoughts (for what is a life but a sequence of thoughts?). Just like a caterpillar the mind goes from one thought to next, so no reason to accept anything or reject anything.

Causality is a construct of the mind.

Causality is a construct of the mind. This is the only thought that is as terrifying as the loss of aham (I) and simultaneously as liberating.

Only the Power of Consciousness creates the sequence of thoughts and mind strings them together and tries to make sense of them. The only utility to thought being those thoughts that point to the cessation of thought!

It is the dual for Ishvara.

Here the notion of "dual" is used in the sense of mathematics or science and engineering, and with the dual in the spiritual path indicating brahmANDA piNDANDaikyam (Oneness of microcosm and macrocosm).

However, the apparent lack of apparent causality does not bother the Self.

The Yoga VasiShTha should only be read by very advanced aspirant, for that is where causality is questioned.

Even reading is unnecessary.

The Buddhistic view of life being a sequence of experiences is not different from nirguNa brahman.

Recall also in this context the dRShti sRShti vAda of SrI RamaNa MahaRShi.

Unstable mind seeks interaction with the world

Unstable mind seeks interaction with the world to make choices but does not want to take the true advice of sAttvic buddhi which is nothing other than the Self, and which is available in the peace of meditation. Getting disturbed the mind seeks advice in the world of sense perception, but the advice of God or Guru in the external world always seems tough and harsh. Hence duhkham eva sarvam vivekinah: the wise see all experience as painful. It is rajas that creates the sense world and the fruit of rajas is pain. Then when that wisdom dawns, what seemed hard to exercise in the sense world, i.e. restraint of the senses, is found to be the easier path. Taking advice from inner Guru is easier than taking it from external Guru.

Don't judge a jnAni ...

Don't judge a jnAni by the mere steadiness of body posture or by your perceived correctness or incorrectness of his actions. For does the world not appear to be full of activity, injustice and wickedness, and is yet the One Self, unmoving and pure and changeless. So until the jnAna cakshu (eye of wisdom) is opened and the world is seen as the Self, better not judge anyone's posture or actions, let alone a jnAni's. This is not the same as being without discrimination, however.

Har zarra camakta hai anwAr e ilAhi se (Every atom shines due to the light of the Lord)

Har zarra camakta hai anwAr e ilAhi se

Every atom shines due to the light of the Lord which is Consciousness of the Self. 

Har saans ye kahta hai hum hain to khudA bhi hain

Every breath proclaims that if we exist so does the Lord. 

Flow of electricity through wire generates heat only if there is resistance to conduction.

Flow of electricity through wire generates heat only if there is resistance to conduction.

So also it is only the ego's resistance to the Lord's Power, which is the flow of Consciousness that generates the worlds.

Surrender (Islam) to the flow and there will be no pain.

Then the mind becomes one with pure Consciousness.

Why does outgoing mind develop egoic resistance? Due to non-extinction of past vAsanas. For that, tapas, svAdhyAya and Ishvara praNidhAnam (islam, surrender). And the preceding steps of aShtAnga yoga.