I would take out a private loan on the paid off property to get the other one squared away

Insurance-  replacement costs.  

Workers’ compensation insurance is mandatory if you have employees.

There are two types of TSP loans: General purpose and residential loan. 

I had replacement coverage insurance and received about 300K to restore the house.  

Do any of the tenants have Dogs (Breed restrictions are individual to each company).These may not prevent you from getting insurance but they may limit the number of companies willing to insure it.

I would like to purchase a three or four Plex and live in one of the units.I understand I can use an FHA loan or conventional loan with only 3 to 5% down in order to get into the property however I live in a very expensive area and the properties I am looking at are currently 700+. 

Another pro for a HELOC is not having to meet a HML's requirements for a loan (insurance, draw schedules etc....)

You can finance manufactured homes with a DSCR loan. the max LTV is 65% for both purchase and refinance.

The loan was personally guaranteed by you, not a corporation.