In terms of things like the name/registry already being painted on the hull, and the ship being built on the ground... well, I kind of wonder if it's occurred to anyone else that this teaser may not be 'canon'. Which is to say, that it might not actually depict anything which will appear in the finished film (apart from, presumably, the design of the ship itself). I seem to recall plenty of early teaser trailers for films that featured nothing from the finished product. They're just teasers, just a nifty few seconds of stuff designed to attract attention and generate buzz. Maybe what we're seeing here is more of a 'symbolic' trailer. That being the case, details like ground-based construction and registry numbers are not as worrisome; they're just kind of metaphorical visual imagery meant to invoke the idea of the film being 'under construction'.
I mean, remember the first teaser for TUC? Did anyone think that the final film would feature the Enterprise flying through space with scenes from old episodes being projected on the hull?
I'm not too worried about this teaser. To my mind, the only thing of consequence here is the appearance of the ship itself... and we all knew it wasn't going to look exactly
like the old 11-foot model, anyway, didn't we? It's just a matter of how
it differs. And this looks recognizably like a riff on the classic design to me. So I'm not too worked up about it.
EDIT: Heh heh... great minds think alike, eh, Arlo?