This is a quality post, though I wish formatting was better. I suggest that you use edit function.
There are two ways to look at the scenario:
1. The launch was a bungled affair that spilled beans before even the appetizer. So, in that India's failure is to Pakistan's advantage.
2. The launch was a calculated move to judge Pakistan's reaction for later reference. The missile was fired to deliberately not hit any target as such.
Any analysis would follow either of these options.
In the first case, we are forewarned & Indians would have a harder time executing their plans. The element of surprise is gone to a good extent as far as Brahmos is concerned. Pakistan has gotten data for reference & an idea to update SOPs accordingly.
In the second case, I hope we gave nothing away - no SIGINT, no reaction time, no actual AD assets' deployment, etc... I am glad that we lobbed nothing over the fence either, which would tell them our retaliation plans or even an idea/confirmation of our missiles' performance. Lack of a reaction was the best reaction in this case. Any further adventurism would certainly not be met with a lack of response. India will have to do something else to provoke a response and I think planners on this side must have already gamed alternatives for maximum effectiveness if & when an emergent situation demands.
In both the above cases we seem to have done well. In the bargain we have a stick to beat India with, diplomatically speaking. Any further action from India would be looked at unfavorably by the whole world.
The idea of timing that you have presented is a bit off. There are pre-monsoon rains sometimes in June. These can not be taken as an obstacle whatsoever. Proper Monsoon establishes itself in mid-July. So the window is a bit large here as far as weather is concerned & even the weather may not be a decisive factor.
I also agree with your point about the situation of Russian spare parts. An idea of how Indian weapons procurement works does not inspire confidence in Indian ability for on-time procurement, unless they have good deal of reserves built up. Any conflict that prolongs would be disastrous since it would draw in other powers & would spread to India's disadvantage in more ways than one.
Lastly, we know that Modi's go-to strategy to regain popularity is to target Pakistan to rally his base & get broad support. In cases he tries something like drama of Surgical Strikes, or Balakot Crow affair, Pakistan's response should be disproportionate. Do note that our responses to both of the above did not produce results that proved to have deterred Modi. He sold 26 Feb & 27 Feb as accomplishments despite them being duds. I agree with
@MastanKhan when he said that PAF should not have let any SU-30 MKI leave the arena without a missile on its tail. Had we targeted them effectively, Modi could not have hid his failure and therefore would have paid the price - no matter how dim / dumb his supporters are.
I hope PAF stays vigilant & PA stays alert to deal with any misadventure from the East.