@Gilberto Rodriguez Well...I have a group that does NOT charge and there are no things to buy, just free knowledge.

So, keep that in mind as well. 

In addition weather makes a difference as well.. snow ?

AirBnB guests were (generally) younger and more prone to having entitlement issues, leaving the places messier, etc.Do you have your sceening parameters set the same for both?

I think most of the ones I have come across are either a) Very well off, and diversifying, or b) much later in their careers and they are using a vehicle they know (RE), just in a more passive way. 

In declining his offer I would go ahead and set the expectation that you are granting him a promotional rent for this lease period only  and he should expect a rent increase at lease renewal.

Between all of the set up work, creating your listing, responding to guests, setting door codes, scheduling cleaners, paying bills, reviews etc it is not hard to log 2+ hours per week.

We had to wash the walls, then prime and paint them, as well as washing and painting the cabinet faces in the kitchen (building is in a C neighborhood).

Well, dad decided he wasn't ready for the ensuing responsibilities of being a husband and father and skipped out, leaving mother and daughter in the lurch.

Hold, continue building equity, and in the long run you will do well.