Some of the more common contingencies include: financing, appraisal, title, and inspection.

It doesn't bind you with common liability risk the way a partnership does.The legal website NOLO.com explains it this way:https://www.nolo.com/legal-enc...Joint Venture.

This is very straight forward and common situation.

Andrew is a common name in my family"

@Austin Shute if you intend it to be storage for the whole building, you'll need to figure out how to connect it to the common areas / hallway so all tenants can access it.But usually what folks do in this situation is combine the top floor with the closest unit and make it a bigger unit (a "townhouse" unit), rather than using a top floor for storage for the whole building.You might have to remove a door or two to connect the two units so the building inspector doesn't think you're going to keep renting the top floor as an illegal 5th unit, but as long as that's done I think you might be able to keep the bathroom up there.

I live in Houston where this setup seems relatively common but am not sure if that comes with tenant issues around a shared yard, etc.Thanks!!

Very common for the lockout policy to be outlined in the lease.

Commonly, not always. 

It is a small urban town so crime in urban areas is common but I'm not afraid to walk around. 

Not impossible, but far from common.