I would try making the right wall the front wall. That will allow symmetrical front soundstage. Your speakers are small enough that they will benefit from close placement to the front wall, which will improve their bass output and reduce midbass smearing from front wall reflection. They can be placed wider for more realistic imaging, especially with center channel filling in the middle. Sidewall reflections will be much less noticeable, probably not needing damping ymmv. All surfaces are hard, some are concrete, so you will benefit from damping as much midrange reverberation as possible to gain dialect clarity and better tonal texture. Carpet or rug, ceiling amplitude diffusion, etc.
The sub is probably better against a flat wall than in a corner, or at least put in the solid wall corner, not the corner with thin door with closet behind (same as alcove which is acoustic no-no.) Sub placed right behind listening position allows turning it way down to minimize bass modes, while still achieve proper bass SPL because you are very close to it.
Adjust speaker and sub distances as accurately as possible in your receiver.
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