Call me crazy but I think Tebow actually might be a pretty (good) QB. I actually think the Bronco offense COULD be pretty devastating.
Why?
If they get another fast receiver like the Steelers' Wallace and started actually play action passing on first and second down, they could rip off so many big plays. Just like in OT, everyone in the stadium and watching on tv, expected RUN on first down. Everyone. In order to stop it, the steelers had everyone up close to the line of scrimmage. A simple play action fake and slant ends up being a huge play.
I don't think he'll ever break Drew Brees' record for yards. But Tebow's offense might be just as devastating if Denver can maintain their tough running attack, add another fast receiver, and pass on first down instead of third.
That second quarter was a perfect example of what Tebow and Denver could do to teams with those devastating play action fakes and deep balls.
Even more impressive was how Denver chewed up the Steelers' defense.
You could have done more here. You touch upon upgrading at receiver which should be a big priority this off-season either in the draft or free agency. However, you could have gone beyond this. First, I'm not sure I'd go after a stud (i.e., Desean Jackson if Philly looks to franchise and then trade him) and thereby pay said stud 9M per when it's likely the guy will only get 50 or so catches. Rather, imo, they should pursue a burner with upside to, like you said, stretch the field, and keep the safeties honest, ala Torrey Smith on Baltimore. A young draftee like this or a free agent with such skills would be valuable here. In addition, a killer tight end may do even more damage. A big, 6'6" target who linebackers, safeties and corners alike have trouble covering, like Jimmy Graham or Antonio Gates, would clear the way for said defenders and keep them more honest when defending the run on many other plays, thus paving the way for bigger Tebow, McGahee, and Ball runs at times. Obviously this is much tougher to find than say a burner at wideout. However, it's not unlikely. 10-15 high quality pass catching tight ends have entered the league in just the last five to ten years. Why not another one?
More importantly, while many see Tebow as a poor quarterback, a fad and someone who will be figured out next year by defenses, I feel quite the opposite could be true. Many first year starters struggle. Their completion percentage and accuracy typically rises in the coming years. So if Tebow is so awful, as many proclaim, now and the team is winning, how good could they be when he improves from 48% accuracy to something as reasonable as say 55%? Might defenses catch on? Sure, it's obviously possible. Maybe even likely. But they're not running the Wildcat here. The Wildcat has sort of gone by the wayside and one reason may be, and I'm speculating here, that defenses have caught on, playing teams like Miami with Ronnie Brown or the Jets with Brad Smith or the Browns with Josh Cribbs back there, seeing it one week and then again a couple weeks later. The Broncos on the other hand are the only team who run their style of offense. Teams within their division may catch on but their coordinator can or should add some wrinkles and Tebow and his surrounding cast could or should improve thus making it much more difficult for defenses like you said. Imagine if the Broncos did add someone like Desean Jackson who defenses would have to account for on every single play. And someone like Rob Gronkowski. The offense would be so tough to defend. Jackson stretching the field or doing hard dig routes. Gronkowski blocking on some plays or being a huge mismatch for any defender on others. Royal doing quick slants, acting in the sort of Welker role. Thomas being the big, go-to guy much like Keyshawn, only faster. And oh yeah, their running game being an insanely difficult guard given all the receivers who would have to be respected.
Again, just my opinion. And a lot would have to happen. But they already have the qb and rb's. They already have a stud o-line. They already have a few wideouts in Thomas, Royal and Decker. The addition of a burner and a stud tight end could do wonders here. That, and Tebow's improvement. And I see no reason to think that can't happen.