Is there any way to see kill/death ratio per weapon, map, or kit?
Subject says it all. I really wish I had those more finely grained statistics but since it's not on the battle log site, I'm guessing it's simply not available (unless I've missed it somewhere).
I don't think one exists.
http://forum.ea.com/eaforum/posts/list/7613964.page
Also, it seems previous BF games did not have a public API. It was just sites using existing sources to get the information, much as it seems a site like BF3Stats is doing.