I would certainly rather have the tenant pay $3,500 and personally pay an extra $100-$500 for a whole new unit. 

Almost to the point where it felt wrong.. netted more money with almost no extra effor.

This studio transformation would bring me about an extra $500-600.

You'll need a cleaner who is willing to do some extras (for extra pay) such as receiving packages for restocking or replacing worn items, or being the local contact person in an emergency. 

So, you could make some extra cash renting out your own place, or a room in your home, but only for a handful of days during the year, and only at your personal residence. 

The reality is the opposite - if it's not in writing then the PMC doesn't have to provide the service or can charge extra for it!

A 4 bedroom unit would be in the $100K range.This means I'm looking for older homes in the older parts of the city.The buildings may be more rundown and need some extra maintenance but it makes it easier for me to get cashflow out of them.Your approach should always be to find deals, offer 15-20% under asking price, be prepared to negotiate, and lean on your team of experts for the heavy lifting. 

Quote from @Sean Pedeflous: Yes, I recommend charging extra for pets.

However, by doing so, I'll be paying $1000 extra each year towards my mortgage, reducing my cashflow to $4000/year.

If you show someone how  seller financing works, the extra verbiage, etc., is too much sometimes for them.