The rest of the time I would rent it out as a STR.

The premise of the time value of money struck me: "Money in hand today has earning potential, and we can turn money today into more money tomorrow by investing it."

After 30+ years being a part-time real estate investor.

My husband and his partners sold their company, and he is transitioning out of full time employment there in the next couple of months.  

Get a bank statement to cross-reference their paychecks as most employers now direct deposit.You'll also see if they have a savings history or are living paycheck-to-paycheck.If they are not paying rent right now and have no savings, how well do you think they'll be able to adjust their budget, so they can pay rent on time?

At this time I do not have any money in an IRA its in an account provided by my employer.

You're in the business of flipping houses, so any self-employment taxes on the ordinary income most likely aren't being calculated in QB. 

BO is ramping up their employment now, my new tenant will be working with HR at the site and will be onboarding lots of folks over the next 2-3 years!

But this time Trump has a trifecta!

Tenants stop paying rent all the time.