HERE IS THE ANSWER: Axiom rep also mentioned the ports, so flush-mounting is out. The only way to properly mount the AS series behind a fixed screen is to build a "sub-frame" or "box" to mount the screen about 4" out from the wall. Then the speakers can be mounted behind the perforated screen, with less than 1" gap from the speaker to the screen.
I think I'm going to try it. It will save me some major coin, and I'll get what will probably be superior surrounds in the QS8's (without cutting holes in the "visible" walls). Since I already planned on twin EP's, I will now have a complete Axiom system! I don't fully know why Axiom speakers are so attractive to me, as I have never even heard them in person... But I've read enough about Axiom from many people on different websites--filtered out the garbage--and come to the conclusion that I won't be disappointed with them.
So this is my new/current plan:
Center - W150
L/R - W22 X 2
Surround - QS8 X 2
Rear - QS8 X 2
Subs - EP600 + EP500 combo

WOW! That should be a very nice system. It's almost a shame that the W22s and W150 won't be visible. Be sure to let us know how it all works out.

Excellent choice! Perhaps you'd like to purchase my extended warr---oh, wait, sorry, channeling used car salesman.

In all seriousness, it sounds like it should be a great setup. Let us know how it goes, and post pictures when you've got 'em!

How are you going to work a EP500/EP600 combo? Is the 600 horizontal?

Yes, the EP600 will be horizontal behind the 2nd row seating. The EP500 will go up front, beneath the screen.

Building the screen out a few inches sounds like the right answer. That's going to be a REALLY nice system !!

Which brings me to the next question/problem: How exactly should I build that frame? And won't it look awkward? How can I make it look cool? Should I paint the 'box' black, or match it to my wall (beige)?
NOTE: I have no room for any sort of curtain to put around the screen. It will be right up to the ceiling (well, the left half will be), and I have about 5 inches on either side of the frame. There just happens to be an electrical outlet in the upper left corner of the wall. Perhaps I could put some sort of "rope light" around the left, bottom & right sided for ambient lighting... I'm not so sure I like that idea, though.
Any other thoughts?

I don't have any specific recommendations about framing out the box itself, but in addition to mounting an acoustically transparent projection screen on the front, I'd cover the top, bottom, and sides of the box with some acoustically transparent fabric. That way the sound can travel more or less freely in all directions from within the box.

I’m also building a screen to mount on the wall. I plan to rip some 2X4’s in half and screw them to the wall the size of my screen. Paint them all black, then rap the material over the 2X2’s. Trim the edges with some MDF and paint them to match. You could do the same, but just don’t rip the 2X4’s down. Space the studs so the speakers are in between them. You can build the frame and mount it with some angle brackets that you can find at any hardware store. Just mount them on the inside of the studs. Then trim it out.....

Is there a review/listening comparison of the M22 and the Architectural series W22 anywhere on this site? When you add the necessary stands to the cost of the M22's, the price is similar.