Maybe a sign like Steve mentioned or some coming soon  posts on Craigslist might help your cause but personally I wouldn't do it.  

I'm not sure I would take a note simply saying, Allow the companion pet, without a doctor's statement actually saying the person requires it for their disability, but I'd probably check with an attorney first before causing problems for myself.  

Evicting him could cause you to miss your move in date, which I quite honestly think you will anyways.

@Joe Kalis  I agree completely about the concern about water. if we remove the tub we will be able to see if the leak is caused by the plumbing or the poor seal around the current surround.If we use a liner and the water damage is caused by plumbing I will not have solved the problem so your point is a good one. thanks

The Deed: Seller shall convey or cause to be conveyed to Buyer or Buyer’s designated grantee good and merchantable title to the Real Estate by recordable general Warranty Deed, with release of homestead rights, (or the appropriate deed if the title is in trust or in an estate), and with real estate transfer stamps to be paid Seller, unless otherwise designated by local ordinance.

Its hard to imagine how anyone could incur any liability or cause much damage from caulking something and using sand paper.

@Zack Parker  welcome to BP and, man, I wish you lived in NYC cause my softball team badly needs a ringer.

Seems kind of unfair to have to pay for damage caused by someone else's house fire.

IMO: I would stay away from an ARM, you have to many risks involved that could permanently harm your future RE career.

In Virginia there is jargon to the effect that you are responsible (if you are a landlord) to provide livable conditions and it may cause further problems for you if they say you haven't been providing that even when they haven't been paying you.