room placement question

You might want to consider listening more near field if possible in order to avoid undesirable room effects. Small monitors would be a ggod fit for that.

Or the other way to go for a wide variety of potential listening locations would be with omnidirectional speakers that radiate sound in all directions. This will tend to fill the entire room with sound more evenly and lessen the effects of openings to the side and such.

I probably should've included what speakers I'll be using... I currently have Dynaudio C1 monitors, so this would go well with Mapman's suggestion of listening more near field.

I don't think it would be as bad as some speculate. Other than this questionable it seems to be an excellent space.

I'd suggest 3 things. 1) Install solid wood panel sliding double-pocket doors between the great room and kitchen. 2) modify the main entry to the great room so you can install another set of solid wood double-doors (pocket or swing into the room) so you can have privacy without completely annoying others. The solid would double pocket doors should absolutely minimize any concerns.

3) I suggest talking to the building about using the unexcavated space under the garage as a dedicated media room with maybe a 9 or 10ft ceiling. Very isolated, probably concrete walls, floor, and ceiling. It could almost substitute as a bomb shelter. :) That's the space I'd set my sites on. Just make sure they shore up the ceiling really well.

-IMO

Shortwall setup, eliminating the 'optional' gas fireplace seems to be the concensus.

Experiment with diffusion / absorbtion between the speakers and on the long walls next to the speakers.

Asymmetric rooms have an advantage in bass. In my really awful room, bass nodes simply are not obnoxious. Too many walls, too many non-matching dimensions and some 45degree angles.

I feel the asymmetry problem may be overstated. Along the short wall you could put the speakers 7 feet apart with 4 feet to spare on each side, which should be plenty to avoid strong reflections, especially if you treat the first reflection points.

I don't have any axis of symmetry in my room but am still able to achieve an even soundstage by keeping the speakers well away from side walls.