Told you my room is complicated and challenging
What makes it
very challenging is the restrictions on placement. The room has issues, for sure, but lack of options is always tough. When in doubt, experiment! So here are some things to try.
So pretty much all of my suggestions here are "screw it up in a different way and see what happens!" You might like it better, you might be able to correct it better. Emphasis on might.
Ok, if I were setting things up in this room, I would angle the speakers towards the bed area and angle the MLP as well. Pretty much a corner set up, which would also separate the bed more from the rest of the living space. You MIGHT be able to do this a little. Move the left speaker back 5-10cm/2-4 inches, move the right forward an equal amount. Slide the MLP slightly left and angle it to match. Consider it for a trial, if you think you can live with the asymmetry.
Without that...
My guess is that the bottom right to upper left corner is your main issue. Those are actually double corners, which I have never dealt with, but must be worse than single corners! Given this, I would suggest avoiding pointing any speakers to the right side of the room as best you are able.
Those are for the main speakers, but let me try just focusing on the sub.
For the sub, are you using the "corner" setting? That will roll off the most low bass, wall will do a little less of that, and the third option (in room, center, whatever can't remember but I believe that sub has three setting) will roll off the least bass. So first try at the side wall, try pointing it at the opposite wall then the near wall. Try corner setting and the in room setting for both.
Then try this. Set sub to in room/center. Leave it where it is. Point it to the left side of the wardrobe near your bed. Try to line up the first reflections so they go into the bed nook.
After that, point the sub at the left wall at a slight angle, with the second bounce off the right wall directed towards the bed nook.
Straight at side wall, one bounce to the bed, two bounces to the bed. You should see some variation in measurements. I think that will bracket your options with this position and sub, and if one of those does better than the others, you can dial it in a bit with some minor angle shifts.
For me, I would go with the sub and current set up and enjoy more texture and detail on drums and bass, because that dip at 60 would annoy me greatly. But for Deadmaus? I doubt I would notice a difference that mattered to me, and so would likely use that sub money on something else.
Good luck, and remember that the only thing that matters is that you like the sound in the end.