1. No. You can work around it by editing contract amounts, signing coaches to different roles, lowering their stats and then making them head coach etc but the numbers don't change/grow.
2. No. By the time you reach current day, most teams only have 2 of their current uniforms, only a few have 3 or 4. Most of the historic uniforms update properly, a few are missing or come in later than they should.
3. Yeah, I play with a tiny cap growth boost/51 or 52 I think and the cap has never been an issue, wouldn't be an issue without the boost either.