Even from the just the official trailer, I think a timeline presents itself:

1. Early in the movie Wanda and Vision are resting at a hotel room. Probably lots of exposition for the audience.
2. In the same scene, or one very shortly thereafter, they head out on the streets and are attacked by Proxima and Corvus.
3. Vision, wounded in some way, is saved and defended by Wanda.
4. The rest of Team Cap arrives to help.

We can guess from the staging of the fight this is the introduction of Cap in the movie–the pause, zoom in, walk out of shadows is every inch a heroic introduction. I think pretty confidently these scenes happen very early in the film (not to mention the suspiciously happy “calm before the storm aura” in the hotel), and Vision absolutely is not going to die that early on.

As for why we haven’t seen Vision or Wanda in any other scenes besides Edinburgh, could be several reasons:

CG isn’t finished, to increase dramatic tension by not letting the audience know how the Edinburgh battle turns out, their scenes include major spoilers we can glean in a glance, they actually are in some of those scenes but they’re purposefully leaving them out, or they are purposefully hiding a lot more of the movie than we think.

It does seem like Wanda is less interested in the hero side of things right now, with her notably being the only character not in costume. Wanda’s powers aren’t great for undercover operation, for that matter–if Team Cap is trying to stay hidden, Wanda using her powers is a dead giveaway.

Also, you sent this to me some time ago, but I was mostly avoiding Tumblr in anticipation of TLJ and especially avoiding my inbox. Here’s a Wanda and Vis to make up for it! Your Engilsh is great, btw.