I've worn three hats in the seller financing world (as a property buyer, as a property seller offering terms, and as an investor that buys seller financed note). 

I took a break because of my trucking career with being over the road for three weeks at a time.

I gained as much knowledge as possible during my three month course but eventually it came to an end.

There are laws (and statutes with three "T"s) that may apply in these situations on both a state and federal level.

I tried to get the owner of three of the houses to carry a short note but no dice.

I actually found out today that the founder of the company Zack had no intentions on funding my deal from about three weeks ago and was stringing my loan along until today.

The last lender I’ve tried to get a pre-approval had a, imo, patronizing response saying,”Although lots of people talk on social media about buying a three or four unit property with only 3.5% down in practice it almost never works.”All lenders who I’ve tried to give a pre-approval for has tried to sway me to switch to a 5% conventional instead.

I own over 100 residential doors and three smaller commercial deals.

Ask your employer if you can have your pay split up into three deposits, one to investments savings, one to your checking account for personal use on a daily basis, and one to an emergency account you can tap into so you don't have to tap into your investment savings.

However, if the FHA interest rate is lower, I would still go that route and if rates drop refinance  however keep in mind FHA has PMI for life  Here you go FHA has the self sustaining requirement that requires the three non owner occupied  units to cover the entire PITI which with 3.5% or 5% down is virtually impossible with today's interest rates and price level.