The answer to the first question is five.
For how the review works you can see What are the review queues, and how do they work?
Edit reviews don't take long. Currently, there are two pending edits in the queue and it requires two users with 3k rep to approve it.
Other reviews, close votes or flags, can take days because it takes five 3k users to do one review. Also, there are hundreds of them.
I am pleased you are keen to edit but you are still <2k rep and review is there to make sure people don't rush edits and make low quality posts. In short, it is working well ;).
