When you approach a deal as a relationship rather than just a transaction, the opportunities multiply.For instance, I was once approached by a seller who was the father of a girl I’d gone to high school with.

First, obviously leverage is the MVP, but this isn't my first interneting, I know controversial titles get more attention.
Second, I’m a recent convert to Pocketarianism. Bogleheads was the source of most of my forma...

Examples could include:Partnering with other investors to share risk.Using seller financing or lease options.Leveraging creative rehab techniques to save on costs.Negotiating with contractors in a unique way to reduce expenses.I’d love to hear any stories, tips, or approaches that helped you pull off a deal others might have instantly passed on.

It sounds like you've got some motivated and cooperative sellers. 

If a seller doesn't know where they are going, you aren't buying their house.Also, you are probably expecting to get somewhere on the first call.

How can I best protect the seller as well as myself?

Also, make sure to build trust with sellers and research Orlando’s zoning rules—they can really impact deals.

New unit: 4-unit multi family in which 3 units (with existing tenants that will carry over from seller) will remain investment; I will move into (currently empty) 4th unit AND USE as primary residence with primary mortgage.

Your value is, to provide sellers that don't want to list, with a way to get cash for their house and provide buyers with discounted off-market properties they can buy to make a profit on.I am not saying it is not possible to wholesale from the MLS, but it seriously defeats the purpose.Focus on becoming the person/company that offers the most and best value and you will succeed.

Sometimes when placing an offer --  the POS is not yet available - and when you place an offer you can make your offer contingent upon approval of these items... although in order to have a competitive offer in this seller's market you are basically forced to "assume" the pos violations once they become available (usually 2-3 weeks after it's been ordered) -- you should be able to tell if anything more serious might come up on the POS via your own personal inspection.