Taking a look at what you ask I'd say the contributors should have specific groups then, so you can turn on allowing stuff, like:
Maybe a bit more expanded than this, but to get the basic idea, eh?
(And why can't I add text AFTER the table?)
| Group | Edit game | delete comments | upload updates |
| Project admin | [x] | [x] | [x] |
| Project moderator | [ ] | [x] | [ ] |
| Project manager | [x] | [ ] | [x] |