Chatter points towards Hydroman and possibly "The Elementals" (first time I've heard of them tbh). Apperently a number plate on something is ASM221 which is issue 221 of Amazing Spiderman where Hydroman first appears. Fucking nerds.
They've got plenty of time to give the CG a polish yet, I've never had much issue with seeing faces (although I'm more aware of it now you've pointed it out).
I thought the trailer was fine, but I worry it is going to go too big. I liked homecoming because it was pretty low key and not chock full of big spectacular world ending events. This looks like it'll end in a big world ending punch em up. I'm ok with that I guess but I'd rather it be a bit smaller still (if that makes any sense).