Simoney welcome aboard!
Lots of questions there, good ones to ask your FS I'd reckon, but the general consensus with IVF seems to be that the first round is a bit of a trial because everyone responds differently to the meds so it takes a cycle to see how you will respond.
Also I understand not everyone gets frosties so it's not uncommon to have them arrest, there is a fairly standard rate of decline.
In terms of the follies, the best way I can understand it is it's like popcorn. Some will pop early (you don't want those) and others won't get to pop - the FS is aiming to get you the greatest number to pop at the right time. So next cycle they might change up your protocol to get a better result.
It's hard though. Even when we say we aren't expecting it to work first time, we secretly are and it's devastating when it doesn't.
Are you still in the TWW?
I'd definitely start jotting down a list of questions for your FS to answer for you. I did with mine and found it really helpful.