Being renters comes with some compromise like having to comply with their lease.Exercising your legal rights is simply doing business as is necessary.

So far we have compromised...if there's a water line there I buy the ice maker,  otherwise not.  

You are a rehabber...figure out what's really wrong with the unit and compromise with the buyer on getting it fixed. 

The steel your container is made to specific regulations and has not been compromised - 2.

As a compromise, I will charge her for the materials which should be minimal but at least give her some token "skin" to represent her responsibility in this.

"Gutters and grading": water into basement is so common but not a huge deal as long as walls aren't already largely compromised and bowing etc.

The older homes that are structurally sound should remain so, since they have stood the test of time, but only if improvements didn't compromise the structure.

You compromised to satisfy her instant desires.When she starts complaining, remind her; you gave her everything she asked for.

If so and if the price is better on tile then that's a great compromise and I would have to go back and agree with your original post.I thought you were referring to a complete tile shower with a sloped mud pan/liner.  

Trying to solve this issue going in is something you factor into your purchase price otherwise you simply find a property that does meet the correct criteria.Target properties that work don't compromise by trying to fix someone else's problem.