My split personality theater room...

I am building a hometheater in my basement in an existing room which was originally a playroom.
The room is a pretty nice size and measures 284 in * 244 in * 84 ft high.

The floor is carpet on concrete. The ceiling is a drop ceiling with 2*2 ft tiles.

The wall are where it gets interesting....

Sitting in the theater seat the wall behind the screen and the wall to the right is Owens Corning basement system wall which is essentially a 2.75 in thick material similar to OC703.. Both of these walls sit approximately 1 foot away from the foundation wall.

The wall to the left and the wall in the back of the seat is standard single drywall on aluminum framing.

The sepakers I use are Def Tech BP 3000TL in the front a Def Tech BP2000TL as surrounds. I am using the 4 built in subs. The AVR is a Denon 4806CI. The speakers have woofers and tweeters in front and back.

I am trying to reduce some of the low frequency modes (boominess) and i am also looking to improve the clarity or crispness (not sure these are the correct terms) of "busy" soundfileds (orchestras). Individual instruments and solo vocals seem fine..

Questions:

Does the OC basement system wall act as a giant absorber ?

Are therre any guidelines or advice for treating a room which is so non-symmetrical ?

What is the best next step ?

Thanks