My deleted questions continue to count new views. I know that they can be seen by moderators and 10K+ users.
If other people try to open a deleted question (and only see the "error page"), is it counted in the views?
Yes it is, based on quick experiment with this question. When I first viewed it, it had 17 views. Couple of minutes later, it jumped to 18 most likely my own view.
Viewing without being logged in, or without the "view deleted posts" privilege (10K rep), which gives the 404 page, is not counted. Confirmed by quick experiment with the OP here.