Yeah but after he sees that his opponent is a feeble old parapelegic cripple he won't worry about using them. I mean IF Xavier's telepathy does not work against Thanos he will realize that it is his only power so why would he bother. He has fought extremely more physically stronger characters without using a forcefield so why would he use it against someone who can't even walk....
Thanos' superiority complex will more than likely hinder his better judgement and he will let his guard down. I mean really, what would Thanos expect from a cripple?
Since Thanos know's all about Xavier and is not one to get cocky and arogant like that in this situation, no I don't think that at all.
Nobody is immune completely. Sure he met Moondragon and what I have seen she is below Shadowking, Dark Phoenix and Professor X in psionic powers who all three are listed as having monstrous telepathy. And this is WITHOUT Xavier having cerebro or other telepathy enhancing equipment.
BTW:
http://www.superherohype.com/forums/showpost.php?p=6933928&postcount=521
Umm, you even stated yourself previously that the Gem doesn't boost her powers (at least much) and that it just makes it broader.
So really the voters have to consider that Xavier is more powerful than Moodragon, and this is prior to even using cerebro which really boosts his powers.
Actually, I'm glad you brought that up (that the gem does not enhance power). It makes Moondragon rendering Xavier catatonic, psychically, prove that she is at least on his level. Don't believe me? Read Infinity Crusade. 
Well, if Xavier's telepathy works on him it wouldn't matter but if it doesn't then Thanos will realize this and realize that X is no threat to him. If he is no threat than why would Thanos bother putting up his forceshields when he hasn't against physically stronger beings. The explosive will be a surprise strategy, and Thanos would never think in a million years that Xavier would vaporize himself as well as him so that he could win the match.
You don't read too much Thanos I see. The point is, he's Thanos. He's always prepared for every eventuality going into a known fight. Whether it'd be with Tyrant, Galactus, Dr. Doom, or Xavier.
That's the key, surprise. Thanos wouldn't expect a Kamakazee ploy by his opponent to annihilate both bodies. Especially from a feeble old cripple.
It's not whether he'd be surprised by the attack or not. It wouldn't kill him or even put him down, shields or no. I've already mentioned attacks that's he's survived, with and without shields, that's proven that he'd be able to survive an attack of any magnatude that Xavier could muster within 24 hours.
As for being physically stronger, well if they were going to do an arm wrestling competition I could see why that would matter. He is highly intelligent and a great strategist but they aren't going to war, it's two men on either side on the ring. Plus no one could predict that Xavier would set off a nuclear explosion to kill both him and Thanos. Plus I highly doubt that Xavier will be engaging Thanos in battle...
If Xavier's telepathy works than Thanos is beat, if it doesn't than Xavier has no power ability to fight against Thanos. Thanos will look at this crippled old man in a hovercraft and probably laugh his head off. Between Xavier and all his previous matches Thanos probably thinks this tournament is a joke. He will smugly walk up to Xavier and stand tall above his opponent. He decides to finish this quickly as it's wasting his precious time. He pulls a mighty fist high in the air and smashes down with full force that drives Xavier's body flat onto the ground and immediately setting off the nuclear explosive.
Thanos would laugh off a nuclear blast in his worst incarnation. And that's before his resurrection when he was still casually batting around Thor and the Thing at the same time.
Thanos would not have time to react to the explosion and all he could maybe mutter would be "Aw SHi........." as the explosion vaporizes everything within the vicinity. Plus with something that powerful going off next to Galactus would rudely interrupt his meal. The explosion would be strong enough that he would take notice and move to investigate what defences are mounting on this planet. If thanos is not immediately killed in the explosion, Galactus will spot him in a heartbeat and will think he is attempting to attack him. If Thanos didn't suffer a massive explosion he would be a match for Galactus but since Thanos is nearly incapicitated, he would be no match for Galactus. Meanwhile Xavier had left well before this explosion, in his astral form, and is far enough to still hear the loud explosion and see the flash and smoke. He knows what he did was for the greater good and he will than fsoar back home to communicate to Jean and decide what to do next (since Jean was alive in this tournament
).
WINNER THE UNDERDOG, XAVIER
)
