Tools? He's got them.
Rocket arm? Check.
You say he doesn't throw the ball downfield? Most of his TDs throughout his career have been on long throws. He can rocket the ball downfield with plenty of mustard. And ask the receivers about how hard he throws the ball. Go read some interviews. TD-to-INT ratio too high? I agree. And go ahead and check Elway's stats after three years in the league. Take a look at his ratio. He needs to stop throwing 3/4 or sidearm? Maybe, who knows? Brett Favre seems to have done OK with it so far (yeah, he threw a lot of INTs early in his career too, by the way). Carr's not accurate? Try 19-25 in Sunday's game. He threw one legit INT, the other was a batted ball that ended up in SDs hands. Stuff happens. One of his six incompletions was a TD pass that hit Baxter square in the hands.
I'm not making excuses for Carr, because in the end, results are all that matter. But if you want to say he doesn't have the tools, you're going to have to back it up better than that.