10 round seasons work best in my opinion, with 15 perhaps the maximum number of rounds to keep things competitive and interesting. My vote is 10 rounds / season.
As for the current season, from my perspective I don't think I can catch up with coleco1981 in the leaderboard, so the overall winner is pretty much decided at this point. Some people who played in few early rounds resigned a while ago, maybe they would come back if we started next season. So my vote is to end the season early.
Also, I like the F1 scoring you're using for the NES HSC - it allows for more movement in the leaderboard and makes it more interesting.
I think it's fine as it is. Not many people compete anyway and for me personally it's mostly a way of discovering new games I wouldn't perhaps play otherwise.
My preference is the predetermined list based on competitors' suggestions.