1) Dangerden blocks do pretty well from a price/performance standpoint in my personal experience. In belgium you might want to also look around for some of the good German blocks we can't find here in the US though
2) Looks to me like that'd be fine for any 4 hole AMD waterblock yes. Cool product; I hadn't seen it before!
3) Not worth the effort as long as the paint is just a thin layer and not all globbed on and obstructing the fins.