1) I feel it's as safe as any site out there.

2) Not many, most I've seen is 500 or so at a time, give or take.

3) They seem to be better lately, but still happen occasionally.  Your results may vary.

4) https://pay.reddit.com/r/SealsWithClubs/comments/1ttkb3/chairman_bryan_micon_here_with_seal_team_6_on_the/

That's just one link, look around and read some more on the recent issues.