Older homes can be a goldmine for this strategy, but make sure to do a thorough inspection for any hidden issues. 

There were a handful of issued that required some decision making but other than that we have a really good crew down there and they make my job super easy.

Where I can buy and sell unhindered with all the stuff they mention like lenders and legal support and all the rest, would certainly get me started and I'd never leave if it worked.

Wondering if other people have this issue?

If you are looking to buy as an investment property, perhaps it's not a bad idea.If you are looking to buy a new primary with low down payment, in order to circumvent the DTI issue, you need to provide your lender with a lease and two months' rent for your departing residence at closing, so that the debt-to-income ratio is not an issue with your first home being counted against you when buying your second primary residence home. 

The issue with BRRRR is that the refinanced mortgage wouldn't come close to the "1% rule". 

We raised rents almost 100% (on average). 30% upon closing and 70% 3 months later (all were on month to month leases and we gave legal notice). 

They do not believe it was caused by any sort of soil issue. 

Not sure I'd personally buy a property that has a radon issue, but I've worked on large MF deals that build and rent anyway.

If you foreclose on a borrower, and don't recoup the full amount owed on the note and mortgage (plus arrears, legal fees, etc), then you can file a deficiency judgement for the remainder.