Check for cracks in the foundation, condition of the mechanicals, any water coming into the basement, etc. 

I'm not how you are defining a BRRR that works, but if I have a unit with brand new roof, mechanicals, kitchens, bathrooms, etc... and leave 10,15 or 20% in the deal I still feel like I'm winning.  

How will you collect rent when the building's mechanicals are stolen again?

However, these properties generally have a lot of land improvements that qualify as well as certain portions of electrical, mechanical and plumbing that can qualify.

So the major issues in a house are a foundation issue or a structural issue, the next tier down would be a mechanical issue like Electrical, Plumbing, HVAC, then roof - which isn;t an issue a new roof is very common in a fix n flip, and then the outside facade: Brick repair, driveway repair, brick pointing. 

A mechanics lein stops my sale if they actually do the work.

The right idea is going to be the bread and butter.1) Ideal location2) Quality properties over quantity of properties3) 1.25x DSCR4) Intention to hold no less than 8, but ideally 12+ years.5) Sufficient cap reserves6) Mechanisms to enhance cash flow(via alt investing or house strategies).7) Liability protection through no PG loans(if possible), LLC formation, property management and being a diligent landlord.8) Invest deeper, before wider.Now if you're talking where to invest, different information.

So on page 6, Modern Money Mechanics: Federal Reserve Bank of Chicago, it explains that banks don't "pay out" the funds for loans from money in other depositor's accounts.

We have a clause in our lease that plumbing clogs not caused by mechanical/material defects in the plumbing will be charged to the tenant, and if your lease doesn't have similar I would recommend such a clause.

The stock market is a mechanism of transferring wealth from the ignorant too the informed, and that is it.