.+1 for luxury vinyl plank.I'm considering doing a dining room to bedroom conversion for my next project.

I suppose if you had the right pattern, they could work in a living space without looking overly institutional.In the apartment itself, I would lean towards vinyl plank with an area rug in lieu of carpet ... much easier to clean and deal with between tenants.  

I laid vinyl plank flooring.

But if you're talking about a PVC shower pan, no, there is no risk no matter if you dig all the grout out and dig into the mortar below.

it's vinyl.  

We have used the difference to replace the roof, reside, and add vinyl windows. 

The water went through the second floor ceiling, the second floor hardwood floors, the first floor ceiling and the first floor vinyl flooring before leaking into the basement, where it went down the floor drain.

I put in upstairs units, pad and than  thick vinyl roll in kitchen and carpet in bedrooms.

We only have 3 in Raleigh so far, and we prefer 3/2+ SFR with fenced in yard, low maintenance (like all vinyl or brick/vinyl exteriors, etc.), one car garage, etc., so no multi-family for us, although we did look at duplexes in NE Raleigh initially before we came up with a detailed plan -- missed a few great opportunities as we live out of town and the great deals are usually gone in hours, so actually living there will give you an advantage.

I would look at vinyl plank depending on the area and renters you expect to get.