Additionally I would add a benefit for you is that you're in great area to be able to invest locally and can invest in your own back yard as they say.

An umbrella policy for additional liability. 

I know hosts have included additional cleaning fees for violations as a deterrent.If none of these solutions work, you could look into completely independent HVAC systems for the two units, though that would be a bigger upfront investment.

You are a kid and it will be hard to understand exactly what you are asking, where are you getting your money from?

It could go higher with additional work to the house.

Additionally, take some time to drive around your neighborhood and gather information on recently sold properties within a mile radius.

If you do call them best case scenario you get the listing, sell their home and end up with some additional buyer clients that did not end up buying this particular house.

Verify if there are additional adults or other violations.

Quote from @Drew Sygit:My apologies w/my earlier post (below), I was on my phone and not laptop so it wasn't tagging.I will if I may add some additional thoughts...1) The appraisals I've seen in these markets are no where near Zillow estimates. 

All this in addition to 6 other lease violations...