I would lean toward the surround speakers not the M series. The reason I suggested Axion surrounds is they beam sound all over the place. I would also pull your seating forward away from the window as much as possible.
if the cables are connected to the subs they can act like antennas, even if they aren't connected to the pre-pro. If you haven't tried yet disconnect the cables at the subs and see if you still have the issue.
not with the constraints of $200 and no construction.
Adding soft surfaces to the walls may reduce in room sound reflections and you might find that you can enjoy your TV at a lower volume.
You are also assuming that your TV will annoy your neighbors, time for a test, get them involved in providing some feedback of what they can hear.
2 ft for false wall.11 1/2 ft to the riser,6 1/2 ft to front of barleaving 5-3 for back bar and walkway. We cheated on the rear columns and made them 2 inches less deep than the others by recessing the speakers into the walls.