Some require me as the investor to start the process with my own funds and others provide 20% up-front.

Factors such as age, fire protection, condition, use, coastal, etc. could result in different outcomes for the two properties. 

The latter seems to provide a middle ground that could enable professional maintenance oversight while allowing me to retain some control, mainly through tenant communication and management portals like RentRedi.

What protections should I be taking so this doesn’t happen again?

Based on the information provided, it seems like this could be a solid long-term investment opportunity.

Open escrow with homeowner, end-buyer, and self; self transfers contract to purchase to end-buyer in Title/Escrow, and provides T/E with end-buyer's contract with self: agreement to purchase, and fee instructions for self ($10k + difference if any) to be paid out of closing escrow5.

If your not going to own the property in the LLC (you mentioned you are just going to manage it) then you don't need the asset protection.

I work on a local team that provides free educational classes on investing and I am happy to help you with any local connections I have that may be helpful to you in your journey! 

For how long are that service provided?

Best to seek counsel from your attorney and tax professional but if you are going to insist on saving a few dollars, best to provide more specifics on the type of partnership you are contemplating so you can get your hands on something that's remotely relevant.