Curation rewards depend only on the own vote weight (HP, percentage of the vote).
I mentioned this to @acidyo ages ago, I think the 5-minute window is a dumb idea too. Maybe it was there for a reason once, (30 mins, then 15 mins, now 5). I don't see the point and your stake should be the weight.
I don't self-vote so the other issue is a non-issue for me. Flags will sort things out like that it people start taking the piss.