I've had one estimate so far and the guy said that he "exhaust motor" needs to be replaced.

I presume Idaho because of your location but plenty of people buy in multiple states.If the six( 6) month statute applies in your jurisdiction, your challenge is that you don't have an owner or estate rep with standing to provide you what you need to eliminate the right of redemption. 

It must be balanced to withstand market changes.

@Rob Beland I only know of any appliances with standing pilots must be replaced.

There was one of the podcasts, which I can't remember which one unfortunately maybe someone else can include that info, where the landlord would intentionally try to tenant-proof his units by spending money on over-engineered products to ensure they could withstand better.

I've spent a lot of time & money over the past 6-8 months trying to educate myself-got my real estate license and have been reading & webinaring myself to the point of exhaustion.  

Alex,  what I've found in Charlotte recently is too many single family homes are bid up by eager home buyers making it exhausting to find anything with decent roi. 90 mile radius, you still get good renters out that far or are you just flipping? 

Work hard, bust your ***, and when you get exhausted, KEEP GOING. 

And I will definitely check out the Boron book - I feel like I've kind of exhausted my library's offerings, and I'm looking for some new material.

It's exhausting and you can blow 45-70k in renovations, carrying charges in six months easy -- before your FBSO sign or "FOR RENT" sign goes up.