Let me give you a couple of potential sources that may help.

However, we believe he is alleging that we bought the property "as is" and therefore, that we assume all costs to fix the property despite the source of the damage stemming from his unit.

Zillow is not a reliable source for their estimate nor the sale prices they list for recently sold properties.

As a 'mom/pop' landlord myself, I solely post my properties on zillow because that's where I figure most people are looking, and zillow offers an application feature that makes screening pretty easy on me.

I’ll keep educating myself and exploring other sources of knowledge while I continue to save up.

Either source will be just as good at finding a contractor.

One question on liability - - if the house is in the name of my LLC.... and was paid for solely by the LLC - - isn't the point of that "Limited Liability Corporation" just that - if there was an incident - then ok, the tenant pursues it legally - and my insurance companies covers unto $300,000 of it.  

This is my first time using a home warranty company and I'm trying to gauge if there is a legitimate shortage and delay with parts or are they intentionally delaying getting the part, could they find it through another source, etc...Googling tells me this is an expensive fix so I feel stuck waiting on the warranty repair, but the tenant is not happy waiting either.

If you find any good sources of education I think it would be great if you posted back on here because others would probably like to know as well.

Again, Your insurer is the best source of advice on this, but IMO, any client signing this would be very foolish.