Designer and GC will be hitting the ground running on a 4 to 6 week flip.

Legally you are not responsible for paying the agent's commission (the seller is), but in practice you will have to pay the seller enough for them to cover the commission more often than not.

Each state looks at wholesaling differently - in regards to representation, liability, licensing, legalities, etc...   

If you take legal action it will most likley get you nowhere and cost you money. talk with a good RE attorney who is trustworthy and not just looking to get legal fees from you and they will tell you the same thing.

I have worked with her for 6 years and don't necessarily want to burn any bridges, but at the same time want to legally arrive at the lowest tax bill possible. 

Do I need to designate one as the "Primary" tenant who will be paying rent?

Meanwhile the assets deteriorate from stagnation.No legal advice given. 

If you have been paying rent on time and not violating the lease agreement, I'm not sure legally the owner can kick you out:"The sale does not automatically end a lease or month-to-month rental agreement.

They can just go to the Clerk of the Court office and just ask what the required legal procedures are to evict.  

One of the requirements for a multi is that every living unit must have independent utility services or at a minimum 1. legal provisions ensure and protect access to utilities for repairs, even if passing through other living spaces, 2. easements or covenants protect water connections, and the VA approves of a maintenance agreement; 3. there are separate service shut-offs for each unit.