Opening a few walls, updating kitchens and baths, flooring lighting, etc.

Just had the carpets cleaned. 

Can you help a flipper with flooring?

You know the answer.Just be a good landlord - provide a nice, clean and safe place for people to live and charge accordingly.

Others will quote you labor + general construction materials, and you are responsible for finish materials, like actual cabinets, tile, flooring product, and some may bid more of a "turnkey" quote, that would include finish materials.I won't say any one is better than the other, but obviously the quotes can vary dramatically.

Clean facility easy and hard, value add steps. 

Clean the place up and move on.It's highly unlikely he would ever come back to you when he has child p*rn charges on his record.

In response we did a deep clean on the unit and couldn't find any bed bugs but found some possible bug casing and bug excrement.

You will have much higher cleaning/maintenance costs, higher turnover, unpaid rent, evictions, etc.

The apartment probably could use some cleaning beyond what Tenant A will do but doesn't need any serious work.