From what I read, thegoodride has no love for k2. I based my choices off user reviews on forums like this. I didn't come across anything saying k2 bindings destroy topsheets.
Any base plate that's mounted so tight will damage your board and give you that "ring" look.
I am wondering about the ringed thing you are talking about. My old board has a visible ring, but it looks like something left from the bindings being there for so long. It doesn't look indented at all. I am assuming the ring thing you are talking about is something different?