Over the past number of years I make it a point to reach out yearly to each state's manufactured housing division or title transfer bureau to double-check I'm familiar with the local laws and title procedures. 

I fixed the Quadplex up and have been renting it for the past two years with a good cash flow.

It is not preferred as it doesn’t meet my min return or cashflow (~$100 per door) but doable knowing the value add opportunities.

I'm reading a book ("This Time Is Different") about past bubbles, and found the below paragraph really interesting.

Anyone capable of this work or know someone they worked with in the past that I should reach out to?

Keep in mind, if you miss a payment or carry a balance past the intro period, it will become the most expensive loan you’ve ever had. 

I haven't had the best luck with contractors in the past so I'm very hesitant.

In addition to the checklist, I would also request the following:1) background/credit check, similar to tenant screening (need advise on application to use)2) pre approval letter from bank used for refinancing3) referral from current lender and past lenders (not sure if this is typical?)

Seems like in the past, FHA required double pane windows. thanks.

Typically you can request T12 financials, some will also provide the past 2 or 3 years.