You may have other non-financial costs associated with this type of property that compensate for the greater cash flow (e.g. additional risk, needy tenants, tenants whose priorities do not leave room for taking care of your property, etc.). 

Should I be doing anything additional knowing he is running a business out of my house?  

He backed off.My insurance agent advised me in the future to have myself named as an additional insured on the renter's policy so I will be notified when the policy got cancelled.

If you want to buy the small distressed one, she will give you a discount and some bonus cat treats. 

Many lenders will charge additional rate increase if loan is under $150K.

Additionally, consider consulting with legal and financial advisors to solidify your agreement and protect everyone involved.

I cerntainly wouldn't want you to expect time and labor and covenience for free or at a discount but on the same note I wouldn't want you to get price gouged, lied to and taken advantage of either.

If the Tenant’s visitors stay outside of the 14 days; Tenant will be charged an additional $50 every 14 days that the Tenant’s guests are staying in the unit.Is this legal for me to do this?

Keep in mind, the transactional costs of selling a property in Philadelphia with the high transfer taxes and brokerage fees (althoug these are expected to be reduced in light of the landmark NAR settlement that occurred yesterday), adds additional transactional costs, especially in instances where the home was purchased as recently as last year as is the case with your home.

As someone else mentioned there will also be additional expenses when you bring on a property management company.