- Can users with enough reputation see questions deleted by the OP?
- Can they vote to undelete them?
Edit: I erroneously used closed instead of deleted.
BTW: this confusion is caused by the dialog 'vote to delete that post'
Yes. You need 10k rep to see deleted questions and deleted answers from other users.
Anyone can see their own deleted answers (regardless of who deleted it).
Yes. You can vote to undelete your own deleted answers and questions1.
If you deleted it yourself, you can undelete immediately.
If it was deleted by other people, your vote will count as a single undelete vote. You'll need more people to agree with you.
If it was deleted by a moderator, only a moderator can undelete it.
1 To cast an undelete vote, you need to be able to see the post. This means if you are under 10k, you will have some difficulty casting an undelete vote to your own questions (but it's not impossible).