My Studio design - Ideas please

[dave bace]

My wife has kindly let me have the spare room in our house to use as a project recording studio. I'm stuck with the size and construction, so I want to make the best of what I have.
I will be recording voice/overs and vocal to track, so headphones with mic in this space. I have marked where I am thinking of putting the mic for recording, also a listen position and monitor positions. I am using Yamaha MSP5s and may add a sub at a later time, as some of the music I shall be mixing is quite bass heavy, I.E Grime/Hip Hop etc.
My aims are 1. To get the least coloured sound into the mic and 2. to get the most even response across frequencies for mix downs.
I intend to drape off the window space and put super chunk bass traps in the accessible corners, baring in mind that the front right corner is very small.
I was also going to float a ceiling trap above the mix position plus 2 early reflection traps either side of the mix position. These would be 50mm thick, framed rockwool.
My ceiling is plaster
Floor is laminate
left wall, double stud wall
right wall studwall, breeze block and brick
I have uploaded 2 drawn plans with measurements for my ideas, plus a couple of photos of the empty room
Any improvement ideas would be greatly appreciated