And possibly having to modify the work to actual code and standards. 

I have a mix use building in CT. the ground floor tenant is a bar/restaurant that recently moved in. they got a $2M General liability insurance and is asking if that's enough. or if they should get an umbrella. the property is valued at around $700k, fyi. where can i read up on best practices for such a case?

Your rent rate stays the same, your standards stay the same. 3.

Since the landlord didn't lose any rent and there were no damages, I can't see any way this would hold up.If your lease is the standard TAR lease (I'm guessing it's not), there is a clause which deals with early termination.

I fired my property manger in 2 months after they did not perform to my standards.

What are some best practices when working through due diligence at the phase of projecting cost?  

There’s probably asset protection specialists/firms  who will side with your approach but it’s not practical and they are just  fee collectors. 

Conversion rate is extremely low when you get started BUT it will give you good practice speaking with sellers who have a ton of objections.

Quote from @Benjamin Weinhart: Hey Ben, I reference my old boss because I have never seen this practiced myself.

Since you're focusing on Worcester, try pulling up some local property listings and practice running the numbers on them.