Gee... those ideas sounded so easy when I mentioned them.
You do have valid points.
Still, I'd like to see some brainstorming around making the concepts work... especially IMMUNITY.
Rules... What the heck. One could say, whomever gets the final kill, (finishes off a race) wins it. Period. So what if they were a seedy vulture who pounced in on someone's hard work? That's part of this type of political game. A player who employs that tactic probably won't be liked. So with the win, he sits out one round. The next round he enters, he will find he already has a vendetta against him for snatching a controversial win.