For what it's worth, when people besides Manning were playing behind the Colts' line this past season and Kyle Orton, bless his mediocrity, was playing behind the Broncos' line, Indy and Denver gave up sacks at roughly the same rate -- a rate that is roughly twice as much as Manning was accustomed to being sacked, and half as much as Tebow was sacked. The quarterback has a lot to do with it. An old pro that knows how to set the right protections, doesn't get caught unaware by blitzes, knows pre-snap who's likely to be open and gets the ball out of his hand on time isn't going to take as many hits. A quarterback who prefers to pull the ball down and scramble if his primary receiver isn't open will take plenty. Of course, Tebow made a lot of plays happen while running around. It's just part of the deal.
Having said that, Denver's line had issues, Tebow or no Tebow. But there's free agency and a draft between now and the season, I'm assuming they'll try to do something about it.
Not all who wander are lost