I agree with you, that there are a lot of question marks IF we moved him to WR/TE/RB full time. But that's not going to happen in the sense that he will be an every down guy.
We do know that he has some strengths, and some unknowns. We do know that he is a good athlete, and I do think that we should in the spring at least try some things with him and see what works and what doesn't. I agree that he is not an every down guy, but with Green at TE, and the RB's like Ballard, Conner, and Perkins, and maybe Elliot, he doesn't have to be. He doesn't have to master every nuance of the TE position to run a seam route on occasion.
I thnk what makes him valuable more than anything is the threat that he may throw a pass, and has a good enough arm to actually do it. The threat of having Newton and Relf in the same formation at the same time is at least something for the oppostion to worry about. I also think that we could occasionally hand it off to him and he could get some yards. He could also possibly catch a screen pass or swing pass. We just have to figure out what he can and can't do and use what he can do.