I'll break this down into some key points.
1. The servers are currently rather pay-to-play, which is unfortunate, but
ChadTheDJ recognizes that and he's working on fixing that. He's adding new slots, and generally making the system how it was originally designed: A place where everybody can play, donor or no donor.
2. The staff members watch everyone, not just the donors. They are looking out for the community as a whole, not those that donate, and they will help anybody who needs it.
3. I don't believe there ever will be any restrictions on the privileges donors currently have (as they are the reason these servers are free to play on, and we don't want to discourage them), but as I've mentioned earlier, there will be steps taken to minimize the negative effect of donors.
4. I'm not quite sure what you're talking about with the Six Flags/Revolutionary War analogy, but I'll make a stab at replying to it. It is annoying when anyone leaves right after the game starts (especially donors), but donors
are punished for this kind of behavior. After joining a lobby, donors get something called 'donor cool down' which restricts their ability to join lobbies for a minute and a half. This is to discourage people joining servers and leaving on a whim (which is annoying to everyone).
Overall, the key points in my response are that I understand where you are coming from, and the developers do as well. Currently, donors make the games pay-to-play, but that is being fixed, and all we can really do for now is wait (or, if you want, donate). So hopefully a solution will be created soon, but we can only hope.