You could buy bead curtains from the dollar store (I think?) and put those in front of the sheets too, to dress it up. either that, or dress it all up with yards and yards and yards of christmas tinsel, christmas lights, and/or artificial vines & flowers. I found a lot of those vines on sale at Walmart just after the season was over during this past year, maybe the dollar store would have something? Sorry about the mess, UGH. You might want to consider trying to keep your options open, and find a way to move. Anybody that would keep a mess like that has real problems, and renting from a person like that is going to bite any decent person in the butt someday.

This is a tough one. How about colorful sheets from Goodwill? If you could attach wire or rope to the outside of the building to some other object(s), attach the sheets from it and then weight them down at the bottoms--or use yard stakes to keep them taut--so it doesn't look like laundry, they could create an interesting barrier.