We allow pets in ours and can charge a fee and higher rents because most of the competition does not.

Tenants seem amazed that I've done things like fix a loose baseboard, tighten the screws on a wall switch faceplate that was coming loose, removed and cleaned off an air return that was clogging with dust and pet hair and basically just take care of little things.  

I'd also love advice on marketing the unit, as well as any "gotcha" items I may want to include in the lease - such as itemizing penalties or consequences for disallowed pets, extra residents, maintenance and notifying me of problems or issues, inspections and frequency, etc. 

Also what are the Pet requirements?

I have a pet pee..if the company don't have a website then I don't do business with them. 

My numbers looked like this at the time of purchase:$240,000 price pointEach side rented for $1,100Mortgage was $1550I live in half, rented out half to a roommate for $550 and collected $50 pet rent from the cats on the other side - totaled $1700.

my understanding is that first, last, security deposit and key can only be charged.no other application, credit or pet fee can be charged.

Do you have any pets?

Putting in a good fence is making it additionally pet and family friendly too.Exemplary!  

But four of them allow pets and yours does not.