Not necessarily disagreeing with you but:
A rider who holds his nerve (something that should not be underestimated) and scores the most points on the night is a deserved world champ. That's why I still prefer the one-off final concept.
A GP series can be, and has been, won without winning any individual rounds that season (step forward Mr Loram). Consistent, yes, but not outstanding at any point.
I wonder if it's possible to win a GP series without winning a race at all? For instance, finish 2nd in every heat, s/f and final, while the big wins are shared around?