Teams where Kaep would be an obvious upgrade over the current starter;
Jets
Dolphins
Browns
Bengals
Texans
Jags
Indy (Until Luck returns)
Giants
Bears
Vikings (Until Bradford is cleared)
Cards
49ers
He's also not decidedly worse (not necessarily better either) than Flacco and Tyrod. He would be guaranteed the first backup on every team except the Pats and maybe the Packers depending on how good Hundley actually is. He makes TOO much sense as the Seahawks, Panthers, or Bills backup since those are all mobile QBs that Kaep can at least emulate and keep most of the offense in tact.
There's no way anybody can be genuine about Kaep not being "good enough" to play in the league. If you don't think he's that good that's fine, but you can't deny he's better than guys like McCown or Hoyer, and he's definitely better than older guys that can't go anymore like Palmer and Eli.
Jets and Browns are out because they not trying to really compete. Fins get a pass because Gase knows how to kinda reign in Cutler. Giants are stuck with Eli till he goes down to injury or retires, so they are out. Indy won't sign him because doing that admits to fucking up. The Cards might blow everything up after this year so there would be no point in signing Kaep. Bears are 2 years away from being 2 years away, so count them out. 49ers are waiting to see what goes on with Cousins before committing to anything and have a roster that is not at an NFL level. The Vikings are weird because they have Bradford; who is often injury, and Teddy, who is coming back from a traumatic injury. I'll excuse them for not want to make the QB situation any more chaotic. That leaves teams with no excuses:
Bengals
Jag
Texans
Bengals: With Kaep instead of Dalton they are at worst 1-1. They would have murdered my Texans. I guarantee they have an offensive TD.
Jags: Would be in play to win the division. Kaep with those weapons, that running game, and that DEF would be filthy.
Texans: Was never in play for many reasons chief among them being the owner gave 500k to Trump. For basketball reasons I mean football reasons we just drafted Watson in the first round and the staff really believed in Savage. Like REALLY believed in him. He would have started 2 years ago if he hadn't gotten hurt.