Well...............a TV is "Kissin' yer Sister"....a real letdown unless you like that sort of thing. 
Sadly....unless you do go "TV" and place your seating up real close (7'), you just do not have the room depth required for 2 full Rows of seating.
That can be changed up a bit by building a 4 seat Bar directly behind and up against the 1st Row.
Choosing the right Furniture could allow you to have 5 Seats forward. (Center Sofa w/2 chairs attached)
Of course you should keep your wiring "as is", and at this late stage, trying to isolate the room's sound is pretty much unfeasible. You can accomplish a lot with attractive Acoustic Dampening Wall Panels (3' x 2.5')...but as you related, not being audiophiles speaks of keeping such room accouterments to a minimum. You don't want a rattlin' room....but unless your system is producing in excess of 110 db you won't need much...just a few practical things that are considered "add on-s".
Again...sadly you should have omitted those Windows. They are a hindrance to a correct layout...they WILL need to be covered for effective viewing, and frankly speaking....a well designed Theater...even in a smaller Market Home, is a selling asset. My experience being that having one garners more attention and desire across a broader range of potential Buyers these days than it excludes those looking for an extra Bedroom or such.
Addressing the Daytime TV watching situation. When comparing the cost of a 4K 85" TV against a suitable Projector and choice of screen, the PJ/Screen allows for a more immersive experience while not suffering from reasonable amounts of ambient light. "Reasonable" meaning the light from those Double Hung Windows is muted by effective draperies. The difference between a 85" diagonal sized Screen and one that is 110" diagonal is...how to state it..."bigly" in perception. 8' wide instead of 6', and 54" high vs 42". If you choose the popular Epson 5050ub, a 110" screen with 1.2 gain,and "Ambient Light Resistant" properties will provide 70 foot lambert at a 11.
But they are a done deal so.....onward.
Excepting the already done Pre-Wire (attic or crawlspace above the room?), another option would be / could have been a Retractable Screen that would go down in front of the Curtained Windows. Dependent upon the Curtain's width, sufficient light can be allowed to come into the room around the perimeter of the edges of the Curtain, without overtly affecting the image quality on the screen. Consider this....those windows are in such a position that any Daylight streaming through unrestricted would impact a 85" direct view TV on the wall to the left anyway.
No matter what, not rushing into the build is important. We didn't get the chance to advise before the room went up, so mitigating adverse conditions and working toward your getting the best performance value for the money you spend are the only remaining goals to strive for.
Sadly....unless you do go "TV" and place your seating up real close (7'), you just do not have the room depth required for 2 full Rows of seating.
That can be changed up a bit by building a 4 seat Bar directly behind and up against the 1st Row.
Choosing the right Furniture could allow you to have 5 Seats forward. (Center Sofa w/2 chairs attached)
Of course you should keep your wiring "as is", and at this late stage, trying to isolate the room's sound is pretty much unfeasible. You can accomplish a lot with attractive Acoustic Dampening Wall Panels (3' x 2.5')...but as you related, not being audiophiles speaks of keeping such room accouterments to a minimum. You don't want a rattlin' room....but unless your system is producing in excess of 110 db you won't need much...just a few practical things that are considered "add on-s".
Again...sadly you should have omitted those Windows. They are a hindrance to a correct layout...they WILL need to be covered for effective viewing, and frankly speaking....a well designed Theater...even in a smaller Market Home, is a selling asset. My experience being that having one garners more attention and desire across a broader range of potential Buyers these days than it excludes those looking for an extra Bedroom or such.
Addressing the Daytime TV watching situation. When comparing the cost of a 4K 85" TV against a suitable Projector and choice of screen, the PJ/Screen allows for a more immersive experience while not suffering from reasonable amounts of ambient light. "Reasonable" meaning the light from those Double Hung Windows is muted by effective draperies. The difference between a 85" diagonal sized Screen and one that is 110" diagonal is...how to state it..."bigly" in perception. 8' wide instead of 6', and 54" high vs 42". If you choose the popular Epson 5050ub, a 110" screen with 1.2 gain,and "Ambient Light Resistant" properties will provide 70 foot lambert at a 11.
But they are a done deal so.....onward.
Excepting the already done Pre-Wire (attic or crawlspace above the room?), another option would be / could have been a Retractable Screen that would go down in front of the Curtained Windows. Dependent upon the Curtain's width, sufficient light can be allowed to come into the room around the perimeter of the edges of the Curtain, without overtly affecting the image quality on the screen. Consider this....those windows are in such a position that any Daylight streaming through unrestricted would impact a 85" direct view TV on the wall to the left anyway.
No matter what, not rushing into the build is important. We didn't get the chance to advise before the room went up, so mitigating adverse conditions and working toward your getting the best performance value for the money you spend are the only remaining goals to strive for.
