Looking at the floorplan, what if you removed the bunk beds and move the jackknife sofa there (or a new different sofa) - that would give you a place to sit and read, etc. Then in place of the sofa in the living room, put in a pair of recliners?
Or you could replace the lower bunk with a desk and chair, and retain the upper bunk for storage?
With the shower, it looks like you could enlarge it a few inches by extending it to the wall with the door - maybe make it more rectangular at the same time.