The amount of bacterial adhesion on rectangular arch wire was vmore than round arch wire

yes

There is no evidence about this due to the lack of literature and experimental comparative studies, anyways if you plan to reduce bacterial adhesion on your orthodontic treatment consider that it is influenced by the arch surface roughness and eventually by the coating of the arch.

Likely, the slot's bacterial retention could be influenced by the section of the arch.

Hoping that the answer could be helpful.

Yes it affects

Yes