Hey there.... nice setup for sure! I like the way you have the room arranged, that's exactly what I'd do if I was in that room. If you haven't already, it might help to experiment some with speaker placement to get the best possible bass response via SBIR, while maintaining your soundstage and imaging. The bass traps are also helping, of course.
Regarding placement for your bass traps, if it were me, because the room isn't a perfect rectangle (attic ceiling), I'd do this listening test to find the bass hot spots/pressure zones in the room, and put the bass traps in those locations if possible:http://gikacoustics.com/video-testing-corner-bass-trap-placement/
Regarding the next set of treatments, I'd go absorption at reflection points on the side walls and ceiling, as thick as possible (244s are great, Monsters even better but thicker, 242s work if space or budget is limited), and possibly more bass trapping to make things even better on that front. You can use scatter plates if you wish, but reflection points are probably the one place in most rooms where I want full-on absorption.
I wouldn't worry too much about the window. The speakers are firing away from it, so other areas in the room will be more important to treat. You could put diffusors over them, but if it were me I'd start with treating the rear wall and the reflection points and see where you are.
The doors on the rear wall may limit us a bit.... ideally we want bass trapping/thick absorption, as well as diffusion back there. Perhaps you can mount panels directly to the door(s), or use freestanding panels or stands for those treatments? That way they can be in place while listening or moved out of the way as needed. I'd consider the thicker Alpha Panels here, the Alpha 6As are very hard to beat for a rear wall since they provide both bass trapping/absorption and diffusion.
That should be enough to get you started.... as always you can contact us and one of our reps will further guide you to make sure you get the right products for your room and your budget.