I did use the calibration microphone and an SPL meter, but I feel dumb as I don't really know how to use the SPL meter.
Not sure how to view your pics, but my ceiling is a flat dark chocolate and when the lights are off and the projector is on, I don't get any light reflections or glare. If anything I would like to eventually replace the carpet with a darker color!
You might have some serious issues with vibration and noise while it's reproducing bass, but generally speaking subwoofers can be at any height. You do want to be a little bit cautious about having a subwoofer at the midpoint of a wall, as typically there are a lot more room modes to excite thereWould it be ok to place a subwoofer high, like on top of a 6’ tall entertainment unit?