Are you saying this was submitted to the investor and the investor denied the short sale? 

If the original lease allowed subleasing you can't unreasonably deny the original tenant the opportunity to sublease to a qualified candidate as a one to one replacement of a departing tenant.

She can not deny the math.

Signed purchase offer and attorney wants to add a contingency after Chase signs it to the effect of "....must have a marketable title upon title search"   Attorney said they could deny this and continue on or walk away too. but he's using the wording to give us an "out" if there is a title issue and to get our earnest money back.  

Not saying you can't be cordial, but don't forget your #1 role and don't give them the chance to use or abuse you in any way.Best of luck to you!

@Jason Koehl it is ultimately your job (or property manager's if you have one) to approve and deny the tenant.

I would deny the requested showings as well based on my clients interests.

From what you're saying it's not as though the tenants are abusive to the property so their sloppiness can't "make it worse" if I'm understanding you correctly.  

Your lender, unless they are private, will likely quickly begin denying you loans and you can quickly find yourself in over your head.Also, if you have that much cash to play with, and you intend to rent when you get out there, house hacking might be a great strategy for you.

It seems easier on you to deny the puppy and keep your two dog limit.