The biggest flaw in the SE system by far, is that it mixes up domain knowledge with moderator suitability into a single mess called “user trust”. We need to get rid of that system.
A good domain expert doesn’t necessarily make a good moderator, or vice versa. Votes on answers should count towards domain knowledge reputation. Doing tasks like edits, close votes, flagging, reviews should count towards moderator reputation.
With this in mind, I think your proposal is quite sound, much better than what SE has currently. Maybe just three categories though?
- Site experience. Everything you do counts for this - like the SE rep system.
- Domain experience. Votes on answers count for this.
- Moderator experience. Edits, reviews, flagging etc.
Maybe come up with some fancier names for the categories though.