Your attention to detail and willingness to investigate is remarkable and inspirational. I think any manufacturer of a good speaker would be lucky to have you review it, because you're going to wring every ounce of performance out of it. You're not going to give up and just call it a mediocre speaker because you don't get good results after half an hour of fiddling.OK, that was a mouth full. The short answer is: adjust the speakers' pitch for best image clarity. The slightly uneven wall issue really had me thrown though until I got mirrors and lasers involved. Details!
In my reading of threads about projectors, I have come across many instances of people trying to get their projectors to square up to their on-wall screens, and the culprit is often that the wall is not level or square itself. So this is apparently not uncommon in construction, and for a dipole speaker this will have a significant effect on performance. It's good to know how sensitive these things can be to such issues and to be able to identify what the problem might be.