In my opinion you should not straighten that wall- unless you get a striped carpet you will probably never notice it.
I think a corner sofa is too big for this room and you would be better finding two sofas- I would look to find one that was 2.1m long and another that was about 1.5m. I think you should also be able to find plenty of choice that is only 90cm deep.
To get a comfortable viewing angle on the TV I would put the TV on a bracket that hinges outward meaning you can store the TV flat against the wall opposite the window, or move it into the corner to suit both sofas. This would mean that the aerial and sockets need to be on the wall opposite the window, at the height of your eyes when sat down. And I would put the wires about 60cm from the corner if you are getting a 42” TV which would probably be as big as you could possibly consider for this space.
Q
Thanks for this advice
Q