That isn't going to help your sale unfortunately as the next owner isn't buying a business really as once you leave, the business disappears.

Can I leave them off of the original purchase since they are gifting me the money (6 figures) or do they need to be on the original deed and then when I get the mortgage remove them?

My question is, how can I structure this to protect myself from a situation where someone sues the LLC and takes the property, leaving me personally liable for the loan?

One of my favorite authors, Nicholas Nassim Taleb, sold me on the concept of Skin in the Game and holding all pundits accountable for prior predictions, myself included. 

Sometimes they don’t like that because you don’t have skin in the game.As for advantages to the seller - are you going to pay them more for the property, that would be a perk that I offer in addition to making a little extra on interest for the duration of the loan.

Putting a long term tenant in a property here that you are BRRRRing won't cash flow unless you plan on leaving a good amount in the deal to do so, but that defeats the purpose of the BRRRR. 

while leaving with happy tenants who will stay!

These will definitely be helpful to consider especially the insurance in my area of SoCal where companies are leaving and prices are increasing. 

Petersburg and Naples the entire month of February 2022 for paternal leave. 

They have more skin in the game then you do.Make sure you get clear title.