It's difficult to give specific advice/feedback with the limited information provide and no photos of the property.

Texas likes to chase the sales price, Arizona limits the annual increase to 5%. 

The second is the conforming loan limit. 

I personally think Airbnb is here to stay but it will be limited to corporate arbitragers and homeshare hosts in the cities that don't currently have ordinances due to the bad PR that Airbnb has around it.

I am limited to where I can put these obviously, and initially decided on putting the upstairs units in the kitchen.

Otherwise, your loss would be limited to 3000 and could not offset your ordinary income. 

So with kids, time is more limited.

@Michael Gabriel please forward that info, I’ve already submitted an offer with contingencies that has a financing clause amongst other things that’ll hopefully allow me to withdraw if things don’t appear at it seems

You should also look into the tax implications of a HELOC vs. conventional loan as I recall that there are now limitations around the deductibility of the HELOC interest payments depending on what the HELOC is used for.

Most regulations I am aware of, which is limited, make it clear that once a property is sold any actions on the part of the seller do not transfer to the buyer.