You bring up a good point. Being a Christian myself, I have always had tons of respect for Tebow and always very carefully examined how he conducts himself, and you seem to have the same conclusion that I have that he "flaunts" a bit.
Really, though, what is the problem here? Certainly he doesn't show boat or act cocky in any way (like the majority of college football skill position players), and when I see him playing to the media it is normally very harmless and/or in a humorous manner (ie, not intended to build himself up) or else he is trying to use the media that obsesses over him to send out a positive message to the world.
I have thought several times what I would do in his situation. On one hand, I would want to be like Ndamukong Suh and shun the media attention and stick to myself, because I want to be humble and I don't want to desire that attention, but on the other hand, shouldn't I use the situation God has put me in, one where anything I say or do will reach the eyes and ears of millions, to do the best that I can and inspire people that there is a God out there worth living for?
I don't know what I would do, but I know Tim Tebow has done the best he knows how.