I think your speaker choices are just fine (M60s, VP100, QS4s). Your QS positioning, though not bad, is less than ideal. But then, so is mine. They are reputed to be very forgiving when it comes to positioning. Though I have no idea if it would be feasible or desirable in your situation, and alternative to wall mounting the QSs, would be
ceiling mounting them. Or, if you have a little space between windows on the back wall,
wall mounting them.
You might want to experiment with placement of your STF-2 (I have one ,too). There are several different opinions as to the best place for a sub. The most common spot recommended is in a corner. Some recommend placing the sub close to the listening position (in your case at either end of the couch). If you placed it between the couch and the patio doors wall (the STF-2 is only 14" wide), that would put in both in a corner, and near the listening area. However, your room will dictate where you place it. Just experiment a little.
Good luck, and keep us posted on your progress.