1. NO, because Vince McMahon hates everyone who ever went to TNA, thus why he isn't pushing Christian.
2. I don't think he is Championship material. He is garbage, horrible on the mic, gets no reaction from the crowd, and one of the worst wrestlers ever!
3. Heel, that is IF he becomes World Champion. It is easier to be a heel than a face after all.
4. 1-2 months only IF he becomes World Champion. I doubt he will though because Vince is never going to push this guy because he has NO CHARISMA.
I'm sorry, but I had to negative rep you for this because isome of your points have no logic.
Point 1 is wrong for one reason. Jeff Hardy. He left WWE due to a drug problem and being very erratic in his behaviour and no-showing events, and went to TNA. WWE let him come back in, and eventually made him champion. Three time champion in fact. So yeah, Vince hates EVERYONE who goes to TNA, and shows that by making Hardy champion. Smart.
Point 2 is your opinion and I respect it, but to say he gets NO reaction is extreme. He gets a very good reaction 90% of the time. And he is far from one of the worst wrestlers. In fact, I and many others are of the pinion that hes one of the better guys on the roster. He's better in-ring than McIntyre, Rhodes, Ziggler, Miz, DiBiase just to name a few (I'd argue Cena, but thats neither here nor there), and if given a decent programme to run with he's good on the stick.
Point 3 depends on the angle he's given. He could easily be a face in an Edge vs Christian feud over the belt (I prefer Edge as a face, but he plays the psychotic heel so well), but it could work the other way round too.
Point 4 I can't fault you on, but your reasons are a load of shit. He wouldn't hold it for long because he isn't a company carrier. Simple. You want your big stars who sell tickets holding the strap i.e. Cena, Orton, HHH, Taker, and Miz etc. And bollocks does he have no charisma, I'm sorry but thats talking out of your arse. You can think that but don't state it as if its fact. Vince may not push him because of his size, but it seems WWE are waivering that standing over world champions.
Onto the topic, I honestly think the TNA run did nothing for Christian. At the most, he maintained his place. He's still an upper mid-carder and I think will always will be. Thats not a bad thing, plenty of upper mid carders win a world title here or there.
I think he would be a great champion because he's a great all round guy in the ring. He can do technical he can brawl, he can fly, he can go extreme, he can sell, and he can tell a good story in the ring. He's good with the stick too, heel or face.
Onto that note, Like I've already said, I think it'd work either way depending on the angle. He's shown in the past that he can do heel, and do heel well, but he can also do face.
I do think however it wouldn't be a massive run. I think it would be a little more than a thank you, more of a 'well done, you deserve this' kind of thing.
Those are my opinions, anyway.