It makes sense for your new build but you'll have leverage something (fixed rate) to get out of that loan. 

I exclusively invest out of state (buy and hold / fix n flip) because cashflow is extremely difficult to find in this area.

Not good I think its a good tool for fix and flip and short term holds but not for long term holds if you have not ability to refi or enough equity to sell quickly even if you do and the sellers loan gets called they are still going to get their credit trashed. . 

Investment Info:Single-family residence fix & flip investment.

We are in both of those markets for fix and flips & buy and holds.

The training is pretty thorough focused on lending hard/private money to other fix and flip investors, or for my own deals for which I could pay myself as the loan broker.

Lenders often consider the whole picture, so keep building that credit but don't let it hold you back from exploring options.Since you're considering a trailer to fix up, have you thought about markets like East Phoenix or the outskirts of Austin?

One golden rule I follow,if it takes a long time to fix/replace when it breaks, don't buy a cheap one.Imagine, this thing breaks in the middle of your peak season and the people who can come out to rebuild are 2 weeks out....It takes at least a day or two to build something like this even if you are super skilled.

We currently have fixed interest rate at 2.85 on one home and 3.25% on the other 

First when I bought them and "fixed them up" and then 10 years later when I had a little better understanding and started doing things the right way.