STRs are essentially small hotels, thus they are usually taxed similarly to what hotels and motels are.

Essentially all legit buyers will get an inspection.

Principal balance currently at 314kProperty Details: It's essentially a "2-in-1" property, with the main unit rented out for $1,900/month and an attached ADU bringing in an additional $1,200/month.

It sounds like you have an un-permitted unit, which is essentially always a risk since there has been no notice to the AHJ that it exists and they can therefore initiate a code case to have it removed in most cases.

Considering that, you are likely going to see appreciation year over year, which essentially will be additional equity you'd capture just by simply living in the home. 

So essentially whom ever is paying them or they single out is the lender you get stuck with and it may not be the best one.

A formal business built on this seems overkill as you’re essentially paying someone for a service that already has standard model.If you and the parnter have distinct business tasks/abilities (i.e. not what you would hire an agent or contractor for), such as off-market lead generation, that’s a different discussion.

I would keep as much liquid as possible and essentially get you to 20% equity or more by renovating the property. 

Still, if you aren't whittling down the number you are analyzing financially to a small subset you see before deciding what to do, you are missing an essential part of getting to the tipping point of expertise in your field.

It’s affordable and easy to set up, but not essential.