I have found that the best answer for YOU is what will allow you to sleep well on your pillow at night without thinking too much about it.

Being that you already have property management experience and feel confident in your ability to manage a single-family or multifamily property, it really comes down to your financial position.If you have a good amount of cash available to put a down payment towards the purchase of a property and maintain sufficient cash reserves (or if you have a partner you can work with who does), then there's nothing wrong starting off with a multifamily property. 

Your primary insurance policy with $300,000 in liability coverage should be sufficient in 99.999% of all lawsuits.5.

And my feeling is for MOST people Solo 401k is sufficient to meet their needs, and an actuary creating a custom plan is “overkill”.  

So I can sleep at night knowing I wasn’t trying to take advantage of them.

But paying down a mortgage does let you sleep better at night too.

I think if you can write a solid letter of explanation stating that you are going to commute to Colorado from Washington for 4-5 months out of the year for your job (and why), that should be sufficient enough to run this as a primary residence. 

I hope you have verified that there will be sufficient equity and that you'll be able to qualify (either DSCR or Conv) for a takeout loan or cashout refi for the hard money.

While a detailed log is often sufficient, adding additional documentation can strengthen your record. 

I work 3rd shift and usually turn my phone off when I sleep during the day and this morning he FINALLY came to the realization that I want him to just make decisions about everything if I’m not available.