I'll start with Dalton, he's improved every week. Most rookies are not going to lead their teams back from the brink, if after 7 1/2 games he looks like he did against the Titans, I don't know how you can really tell the limits of his potential.
He's smart, he has a quick release(Luck does not), he has mobility, that 49 yard td pass against the seahawks he threw to Green, with the defender closing on him shows he has decent arm strength and can execute in a tough situation and he has the mentality of a winner.
It would be a bad move to waste a first round or any other picks on Luck, unless Dalton was injured. Me personally, I say fix that O-line.
As for a lock, not as of now. The fun thing about this team though, is that they haven't realized their potential. The egos aren't there and they're actually responding to the coaches quite well. They may make the playoffs this year, I wouldn't be shocked, but next year and the years immediately following, should be very entertaining. The offense and defense are improving, the defense is already one of the best in the league.
We may have this conference locked up the next couple of years.