Re: Kingston = Tag Team division
I don't think the WWE have much interest in pushing Kingston as a top face at all to be honest. They've shown little hints here and there, but they never follow through on anything with the guy. I think he's perfect where he is, a popular mid-card face who can win the mid-card title occasionally and feud with up and coming heels to get them over, with a tag title run mixed in. That's where he should be at in my opinion. A tag team run at this stage would be good for him, as the OP said, using him with someone like Justin Gabriel would be good for him and good for Gabriel because he should really be doing more too.
But yeh, he's used well as far as I'm concerned.
Marking for: John Morrison, Randy Orton, CM Punk, Sheamus, Dolph Ziggler, Cody Rhodes and Jack Swagger.