Found my answers:
1. Excuse me, I’m currently on 2.0.8pl, so maybe you administrators want to move this post to the revo 2.0 board
2. It’s md5 not sha1
3. Yes, it works. Go to modx_users, change the relevant hash and that’s it. You can find many md5 (as well as sha1) free generators online, if you don’t have one.
Thank you anyway.