Re: chops versus age
The bassist I play with is in his 50s, absolutely exceptionally skilled player and his fingers go like a freight train, the benefit is that he has been playing 3+ gigs a week since he was 14 years old. It's hard to tell if age has started to affect his playing, unless you're constantly pushing the physical limits of your body you're not gonna tell and a lot of players take their technique well beyond what they actually play on a day to day, I suspect he still has a good 15-20 years of playing at a level that would floor most younger players.
I'm still in my early 30s and my playing has only gotten better than in my teens/20s, through a more methodical and intelligent approach to practice + combined with constantly playing live. No signs of slowing down for me yet, I'm still on the up (albiet slowly).