First off remember the phrase "Once a mobile home, always a mobile home".

Are there any resources you'd suggest looking into to understand loan assumption, especially VA loan assumption?

Quote from @Angelous Ultionem: If you're married one fha loan counts for you both won't it?

That said, a VA loan charges you a guarantee fee that is financed into the loan.

I have probably gotten between a hundred and two hundred loans within the past 8 years and I have learned some things along the way that make getting loans easier and harder.

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

Does any lenders offer these DSCR loan terms?

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+. 

The Note/Mortgage for each loan states the dollar amount invested & the % of the total loan by name, for each investor. 

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