Oh, wait, one more question.

I read a whole bunch of posts on here about Aura and I see some people talking about whether the BM color they chose is from the Affinity or Preview or whatever line with the occasional implication that Affinity goes with Aura. In the past, using BM Regal, I've always just picked whatever color I wanted, sometimes a BM color (paying no attention to the color collection), sometimes a color from another company I had matched, sometimes getting a color matched to a piece of fabric or something and asked for the color I wanted in the paint I wanted. It's always worked out fine.

Is there some reason I can't just continue on this way? Some of the colors I've been looking at are from Behr and California Paints. Do I need to stick to a particular BM color collection when buying Aura?

Aura in eggshell is actually rather shiny - be sure you check that gloss level and are sure that's what you want.

Here's an old post you might find helpful.

Here is a link that might be useful: Aura coverage

Skipping the primer is fine, unless he cannot get all the wallpaper paste off. Then he should use Gardz over that.

The painter is going to remove the border and prep appropriatly, which would include priming where the border was. Why not just prime the whole wall while they are at it , to get it all the same?
That is what I would do.