[twblalock]

What authority?

It doesn't take much karma to vote or flag. Well under 100 points IIRC. Past that point, having more karma has no effect on what you can do on the site.

[dang]

Correct. Flagging takes 30 (well, 31) and downvoting takes 500 (well, 501). After 250 you get to set your topcolor. I think that's about it for now.