The issue I've ran up against is the mini-split does nothing against the concrete slab which seems to absorb and slow-release whatever outside temperature it's been in the past 12 or so hours.I'm a complete noob.

But I have some industrial (and other) REITS in my portfolio, primarily for liquidity purposes with some steady dividend income because the REITs have to distribute so much income to keep their tax-favored status. 

We didn't mean to rent out the guest house, but it has been a steady flow of income for our family and can't imagine life without it.Lessons learned?

Business income will be less steady than W-2, but you can take the average and you should be fine. 

@Robert FaragallaI just quickly Googled it (so I'm sure this won't explain everything), but it looks like you need the below:FICO® score at least 580 = 3.5% down payment.FICO® score between 500 and 579 = 10% down payment.Debt-to-Income Ratio < 43%.The home must be the borrower's primary residence.Borrower must have steady income and proof of employment.For the steady income/employment, I've heard they look for 2 years of steady employment history, however I've also heard that time spent in college can apply to that 2 years.

They like the idea of a steady flow of passive income if they are in-between projects.

The problem is that it’s really hard to find a nice temperature for every room (a few of them get really hot, and the tenant constantly keep the windows open.).

I purchased a house in the Lacey, WA in 2019 that has seen steady appreciation  recently but we are now seeing distribution centers popping up just miles from our house.

I have a little bit of free time and I currently work a steady 9-5, but is there any real benefit behind getting your real-estate license for someone who's 20?

I know REI is a slow and steady race, but I would love to have +20 doors right now.