All rooms have permanent stains from urine and other things in multiple spots that a professional cleaning service could not remove. 

Once again you build a database and get marketing.From here word of mouth will keep you busy unless you do a crap job of course :-).Lastly I have been sent LOTS of clients from the professionals I work with.

Example of issues: front window squeals when windy outside, lots of concrete around pool is severely cracked.

Once they lose a case due to procedure, they become bitter and remorseful for not spending the extra money to have it done professionally. 

. , You probably want to get a professional to do this if you are not confident.

Bed bugs can hide in any kind of crack.

Philly is a very tenant friendly city, and professional tenants know all of the ins and outs to work it to their advantage.

There are some professionals in the BP community that may also be able to provide the advice you seek. 

As always, seek professional advice. 

Any recommendations I make are based on experience, and not the advise of a professional in fire damage remediation, I am not a lawyer, and any advice I provide you may take with a grain of salt.In regards to the tenant, atleast in NYS, it is their responsibility to have renters insurance to cover their belongings, you are not required to compensate them for any losses.