Off the top of my head…

1. Removing spam
2. Reviewing flagged posts and actioning them as needed
3. Ensuring that posts follow the community rules
4. Organizing events and contests for your userbase, if applicable

It can definitely be a thankless job at times, but also very rewarding to see the community flourish.

Might have been something on your end, or simply server issues. Reddit has gone offline a few times today already. I was able to delete a few old accounts earlier today without issue.