My question is, can I make improvements with the proceeds of the old house to the vacation rental including new floors, carpets, and furniture?

During the showing, ask questions about the type of furniture they have (will let you know if they buy nice things or Ikea stuff).

I found all my furniture on craigslist.

I live in the bedroom downstairs, rent out the 3 bedrooms upstairs, and plan on converting the den to a suite-like room to airBnB when I get some free time - mostly just needs some paint and furniture.

I drove by the other day and noticed their patio furniture was still there, so I assume furniture is on the inside as well. 

But let's say she had shoved furniture into the attic, on top of the water heater pipes, that eventually leaked through the ceiling & created a repair that cost $500.

Sometimes I deliver flowers, sometimes it's furniture, other times I just run a quick drop and hook.

We get a lot of business travel since it's the furniture capital of the world.

Who owns the furniture?

The yard is full of car parts and furniture (or I like to think of it as potential).