So i noticed the nerfing of Race payouts altogether and it is disappointing...but I also tried GTA Race last night for the first time and I didn't care about payouts anymore. I still wound up getting a medal completed for winning bets but it was all good fun.
If they nerfed Jobs, I can't notice it b/c I'd never played the Martin mission Jury Duty or something which I'd noticed but never done since I figured 1-8 ppl would be something painful. Took two tries but me and the guy in my car got 20k while the other 2 got 10k. I noticed missions have been reducing payouts on replaying them but if you haven't touched these missions, their overall main payments remains the same. Another example is I'd done Titan of a Job at least 10 times since it started paying $10k. I'd assumed it would keep loweing but I still got half (5k) last night. Armored trucks still pay out nicely and survival still kicks out 20k as we tried and survived the Beach Bum one.
Earning money and RP is far from impossible as far as I can tell. Started at 70 and was 73 within my 2 hours of playing.