1. Do you feel experience requirements are acceptable in Large (Theme/Normal) games?
Yes, at the discretion of the individual mod.
2. If so, do you think they would be appropriate for other types of games, such as Mini Theme games?
I would suggest the following rule (which I think is a codification of current practice): The general rule is that there are no entry requirements for Mini games. Any mod wanting to impose an entry requirement in a Mini game has to convince MeMe that there is a good reason for such requirement.
3. Should Mods be allowed to ban specific players from their games?
Yes.
4. If so, what reasons are acceptable for doing so?
I wouldn't want a closed list of reasons. Good reasons would include someone whom the mod has had to replace before, or who has caused trouble in a game before.