First N=3 posts get denied completely by akismet (I found out that this actually works now and then). First N=5 posts are still not allowed to use BBcode but http://* gets usually parsed as link in the forum software on its own.

Nothing, the editing is something completely different than the posting of new stuff. We would need to write up a plugin to check stuff on edit, and we cannot just use the akismet hooks or anything from posting iirc