1) Room size is just over 2500 cu ft, so not huge.
2) The room has one opening to it, and it is a stairwell.
3) I'm not quite sure how to answer this. It's movie dependent. However, I have set them up with the recommendations from HSU in the one port open mode. Q setting at the lowest and volume at 9 o'clock. Which from 1-9 with 1 being lowest they are set at 3 for volume.
4) so with some movies that are heavy bass, I've noticed the sub dropping out and chuffing or whatever you guys call it. so I figured it would be a good time to upgrade.
5) maybe this answer is biased at what subs I had in mind, but the size of the VTF 15 MK 2 is probably the largest I could get away with before all hell breaks loose with the wife.
6) I watch TV and movies mostly. I'm not a gamer. I do amplify my guitar through it occasionally.
Also I use a lower end Denon receiver AVR-S920W