Should this worry me?

Last night, I finished the rip out for the light fixture in the shower ceiling. It was a beautiful chunk of porcelain, but unfortunately, a bare bulb in such an environment is no longer up to code, and the city chose this as one of the few violations (of the many many that we posess) to write up. The fixture is curious in that it mounts without any visible screws - the screws that hold it to the backing plate are in the socket itself. I'll have to post a photo of this at some future time.

Since this photograph, I've sistered in some 2x3s to hold the drywall flush with the edge of the tile - the plaster and fiberboard combined were about 7/8" thick. But before getting to that point, I took some photographs from the vantage point afforded me.

The following two images are of the same location.



The stud in the foreground at the bottom of the picture is one edge of the shower enclosure.



This is a close up. Note the cracked joist, the tube with a nail resting in it, the wiring joined outside a box, the knob and tube wiring just resting on the ceiling, the beautiful notching and drilling...

The strange part of all this is that I can't figure out the purpose of the copper pipe that necessitated all of this. This pipe, I assume, would be servicing something on the third floor - yet there's nothing there or anywhere near where this pipe appears to run. If it were a radiator pipe, there should be another one accompanying it.

It's just a small crack, right? I really don't want to pull up the floor up there, not yet.

Because really, I don't want to refinish these floors in five or ten years

Most of the rather large third floor is going to become my studio, where I will have space to paint and work in other art media. This can often be a messy process, with a significant amount of paint ending up on the floor.

This is only an issue because there is the distinct possibility that this room may eventually become a bedroom. If that is the case, I don't want the floor to be covered with tons of paint. I'd considered just covering the floor with the carpet that we pull up elsewhere in the house, but the carpet is likely too porous. I've also considered laying down utility grade flooring over the existing hardwood, but this would create issues at the doorways. The final and most likely choice is some sort of linoleum, but I don't exactly feel comfortable with that, either.

I'd love to hear any thoughts or ideas on the subject.