Once you have a business plan in place have a lawyer advise and draw up a legally binding partnership agreement based on that plan.

In fact, on my last deal, I didn't even form the LLC until after the deal was under contract and had approval from the credit union. 

@Cynthia Morgan If you plan to finance with a VA, FHA or USDA loan, the condo development has to be on the respective "approved" list.For FHA or USDA: https://entp.hud.gov/idapp/html/condlook.cfm?

There are probably fancy ways to protect yourself even with an LC, so get legal advice. 

I have money in savings that I can use as down payment, but with not showing much income right now, will a bank approve me?

To build up a fund to hire an attorney to find a legal way to oust owners who rent out their units?

One question that has come up as I begin the rehab process is about how long will banks or loan officers require consistent rental income for short term rental until they'll approve a refi?

May I ask why you are not going to an Attorney to draft the partnership agreement and get legal advice?

I would recommend how to raise money legally and Partnership forming. 

3) if there’s decent equity after his and others’ sweat and material, and he wants to take on the challenge, he’s back at step 1; seeking real legal counsel on his standing with the lender(s).