She explained in her email to me that the chance to save money is too hard to pass up and as is willing to lose her deposit if she opts to move out.

Effectively losing one rental but gaining two more (would move out of my current house with ADU and have it 100% rented).A driving factor is how will selling this asset accelerate you to your next goal? 

Are you going thru Your brokerage to conduct the transaction or by way of being an investor are you simply going to the seller, putting the property under contract and closing or double losing with an end buyer and not involving your brokerage?

Also, check minimum lot size and street frontage as you may need to carve the mobile home park out of the existing lot versus pile onto the existing lot, so if you are trying to preserve the existing structure, you may lose some lots considering setback requirements and access.Your local government may require public water and sewer for a new mobile home park, so be sure to check the requirements and distance to the nearest connections.

Do what you can immediately and start the process to avoid losing more money.

If you own a house and they move out you lose 100% of your income if you own a four plex you only lose 25%. 

I talked to the lender that I'm doing refi now and they said I can only choose one: the line of credit or the refi.I don't really want to lose that 2.6% but still want to do the refi as the rate is low as well. 

I want to weight out all options.Thank you in advance!

I wanna protect myself from liability because all properties will be bough cash so I don’t want to lose any of them.But my question is what LLC structure should I use?

I’m going to tell you a secret... skip tracing is worth it’s weight in gold.