Most maintenance things are not an emergency fix- you have time to investigate the issue, determine if it's something you can fix yourself, maybe call for an estimate, etc but if somebody's heater goes out and it's 3 a.m. in January in western PA that is an emergency fix and it's going to be expensive.

There may be a limitation on your HELOC for speculative RE investing, which could become an issue if banks deem your loan to be risky down the road and investigate. 

Knock does not.On their website under the frequently asked questions, they explicitly exclude properties for investment purposes:Does anyone have a list of these websites for us to investigate further?

You have a lot of investigative work to do before you could consider a STR in your current home.

Depending on the area you are in, this might result in your report being placed in a giant pile labeled ignore that is turned over to the DA's office, or it might actually be investigated and charges filed. 

I would go out on a limb and say the BBB is doing better research on reviewers than Yelp is.I’ve lost trust in BBB ever since investigative reporting exposed shady practices of theirs about a decade ago: https://abcnews.go.com/Blotter...

I have been researching and investigating so many different markets, my head is spinning! 

I have thought about doing this and the cities I investigated only allow 1 of the units to be rented at the same time.

The best way to get a preliminary figure is to run a residual analysis.

If anything, just turn it into your insurance company and let them investigate to determine liability.