Mutifamily is a great investing vehicle and is more easily scaled than SF. 

When he became incapacitated and could no longer visit his unit, approximately 7 years ago, another family member, who had assisted him in maintaining the building, began utilizing the space for storage, vehicle repairs etc.

Both vehicles belong on the scrap heap. 

I have heard that getting funding for MH's is difficult due to them usually being treated as a depreciating vehicle and not as a permanent structure. 

Both vehicles have pros and cons and the optimal portfolio has a combination of both.

The properties are owned by our LLC.Assuming nothing changes from the current tax perspective, what is the "smartest" tax-efficient method of getting this equity out of our investments:1) Cash out refi $1.6m (80% LTV of all the assets) and invest that money in a more liquid (albeit lower return) investment vehicle?

It is an asset protection vehicle if managed properly. 

I section 179 all my company's vehicles.

My wife and I are real estate newbies, but have been investing in more "traditional" investment vehicles for several years now.

I need a vehicle to find and drive sellers to me .