I prefer not to look at the Things' point of view story, however, my opinion is that it is clearly hyper-intelligent and certainly not an animal. It built a spaceship and had a plan of action for survival in the '82 version. Question is, was it violent because it was scared, or because it was a scout for an invasion? It seems to me if it wasn't an invasion, it would have communicated with the natives...
I tend to think that while these things are intelligent enough to be cunning, they're driven by overpowering and aggressive survival instincts. Assuming it's not some alien genetic experiment gone horribly wrong, but a creature that naturally evolved; it's native environment must have been extremely hostile to produce a creature like this. Think of a situation where there isn't any such thing as a predator-prey relationship but it's all predator on predator. I mean these things attack on the cellular level, that speaks volumes of where they're from.
If such was the case then I think it's more likely that it (or it's progenitors) infected or were captured by a visiting alien race before getting loose and spreading. For all we know these things have wiped out whole galactic civilizations before this one stray made it to Earth.
I think the fact that it was alone and that it crashed in an inhospitable environment rather than safely landed in the middle of a nice safe prehistoric savannah, says that it was on the run and the ship was somehow damaged and not the vanguard of some mass invasion.
I think Carpenter says on the DVD somewhere that these things are instinctual mimics are are utterly selfish. So much so that if an entire group of people have been taken over, they'd all still play their parts and try to implicate each other as they don't know for sure who is still human. It's interesting to think that the Thing from these two films might have been fleeing from a civilization full of it's own kind who are all still keeping up the pretence of being whoever they had absorbed, to the point where they're all hunting each other down. Indeed, if I'm right about their native environment being ultra-hostile then I wouldn't be surprised if, when removed from their homeworld, the Things will (eventually) naturally drive themselves into extinction.
Which brings me to communication. I don't think they can. Just watch and see that even when we know for sure that several people had been taken over, there's no indication of collusion or co-ordination. It's a total free-for-all. Sort of like the xenomorphs from the Alien franchise; they're very intelligent but also apparantly totally driven by animal instinct.