Depending on how bad he is in the OF, moving him to first might lessen the negative value of his defense, but it's not going to change the overall value equation much, since you have to be that much better a hitter at 1B to compete with all the defensively-challenged bat-first guys who eventually end up getting pushed there. Same for DH.
What's the typical trajectory of stud minor league player who's graduated from college? 2-3 years to the first cup of coffee? And that's for the guy who everyone thinks can already do it and then actually dominates the leagues he's in while moving towards his peak talent years. Tebow's on the downside of peak baseball age, and nothing in his current skill set really projects to MLB regular level, with the possible exception of the power, even if he were to progress at a normal prospect rate. And he's far from dominating A ball at this stage.
Anyone want to hazard a guess as to how many washed-out MiLB players could put up the numbers he has in the Sally league at age 29? My guess would be a ton, and pretty much all of them are out of the game for good reason.
Just to pick a scrub at random, Joey Terdoslavich put up a .795 OPS in the Sally league in 21 games as a 21 year old while King in 21% of his PAs. His peak was MLB replacement level/organization filler with an 8 year head-start. If Tebow managed to match Terdoslavich's .620 MLB OPS in 150ish PAs, that would be far better than anyone has any right to expect.