Philly as a whole is an extremely block-by-block city with ARV values changing by 20-30k depending on the block you are on.

It is a few blocks from campus and good for student housing. 

I recently bought a small portfolio of properties and fixed one of the places up but didn't put all new flooring in - I put new luxury vinyl flooring in the bathroom and kitchen because the previous flooring was damaged. 

But is there a way to assess foundation damage without actually digging up the basement / tearing down my walls? 

A bad tenant can cause thousands of dollars in damage and unpaid rents. 

Take any repair estimates with you to the protest such as Roof Repair, Mold damage, Foundation repairs etc , and request a Property value reduction due to the condition of the property.   

Downtown environment, 1 block off a college campus.

With that type of funding you could do some real damage in almost any CA market of your choosing.

He broke contract, and I believe TN states that I don't have to pay him back unless I find a new renter to "mitigate damages".

That gives them another 10 days to vacate but meanwhile they can do a lot of damage to my property and the sheriff is now part of the situation.If you can avoid evicting my advice is there is very little help you can get from the law, no matter where you live.