I would build an extra half bathroom but it would destroy the architectural integrity. 

I think I was just impressed by the integration with vendors such as Uber/Lyft, etc, where you have a lot more flexibility with the approach;  variety of drivers/routes, access to several different target markets, and it's less permanent or less focused to just one vehicle like a bus ad or a car wrap. 

It is amazing how many management companies treat tenants poorly and lack integrity. 

Also not sure about other factors.

Factor those in and I don't see any other reason why not.

I am integrating 3 state of the art studios as well as room for a venue/clothing shop.

Roofs maintain the integrity of the rest of the house and should be maintained as such.The price in which you purchase the property should factor in the age of the major mechanics along with windows, roofs, and siding considering where they recommend in their life cycle. 

Also, you will need to factor in the monthly condo fee that would need to be wrapped into your rental rate.If you are setting your price point based on a purchase in South Philly-just south of Washington Ave (which is adjacent to Center City proper) then you will be able to find many potential purchases for rentals here. 

Remember to factor in closing costs and realtor fees if you are flipping for full retail on the MLS.

I highly suggest factoring PM in even if you're doing it yourself.