First thing to do is check with the city or county to make sure the ADU would be permitted to be a STR.

Would you recommend expanding my search area, wait it out, or look into duplexes in my current markets? 

Any info would be very helpful.  

Could be a savings depending on the scenario. 

Would love to see an update on this as well.

Hey I’m 17, living in the US and I’m trying to learn about real estate investing, what are the steps in this business, what’s the best way to go about it and I think a discord would be really helpful for me to understand.

You would have to finish it out to look good but that shouldn't be too hard.What about adding a sleeping area in there as well?

The value of that place would go up $100K instantly with the new look.- Cabinets look good but I'd get rid of all the clutter above.- Take all the cheap prints off the walls. 

I don't want to do a traditional cash out refinance because the house would no longer cash flow and I don't have the funds to buy him out straightforward.

first thing one should do is figure out if they quality the 2  in  5 tax treatment and if the home has appreciated a ton like 250 to 500k which is very common in coastal markets and Denver for instance.. selling would be far smarter than renting. pocket the tax free and find another rental. turning it into a rental you lose that one time tax treatment which in my mind is the very best for real estate.