I'm pretty sure that the crawling person in the earlier trailer is Reed, it seems to be him crawling through the wreckage of the lab after the explosion when they return.
The problem with it is that it also results in the rather cliched plot (even AoU used it) where the main characters apparently become heroes simply for cleaning up the mess they created, just like in the Story FFs.
Its funny, I asked a friend who hadn't been following the production what he thought of the trailer and he said it reminded him of Green Lantern.
Weta did work for it too, but from the 4Chan leak it appears that the big problem OTOY had was that Trank kept changing his mind, forcing them to change things, even not talking to them for weeks then suddenly telling them that he wanted things completely changed, forcing them to scrap work they had done. He is even supposed to have had them vary the size of the Thing based purely on what he thought looked best rather than allow them to keep him a consistent size throughout the film.