In our reviews our lake, pool, size of our house and location relative to everything else gets the most mentions.

It's also really cold outside as well, which he mentioned that "we don't want anyone dying of exposure". 

Since you didn't mention this being in your lease, it sounds like you are incorrect.

One option I haven't noticed being mentioned is to auction it.

If so, as @Brandon Weis mentioned, they come in all "shapes & sizes".You'll get more assistance if you post an example here and ask more specific questions about it:)

As you mention, if you are using hard money yes you are paying more in interest and if you hvae the cash I would recommend using cash over hard money due to the high interest rate that you are paying.

I wouldn't build the ADU just yet because like it was mentioned it cost more than you can really make a good return on.

The things you have mentioned are simple, high level thoughts based on assumptions.

The closest comparison would be bourbon street for college age kids, but bourbon street may need to up its game.  

I agree with Erik, although their are some investors out there that will help fund the down payment/entry fees that you mention, they typically are friends and family that trust you and believe in you.