would you be willing or able to throw up a wall to divide the sink area from the toilet/shower space? separating those two areas has been a godsend in our new home - turns the room into one that can be used privately and simultaneously by two people! if that's the case, 3 and 4 are most conducive to that, i think. if that's out of the question, 3 is still my favorite option. 3 over 4 for me because the shower right next to the door (4) feels a bit weird and i can't visualize how that would look in practice. i would eliminate 2 from the running as well as it looks like the door might bonk into either the sink or the toilet based on that sketch. hope that helps :)