Lead pipes can fail catastrophically with little or no notice.Houses built 1980 or later (date fuzzy here) are typically built tighter with better insulation. 

In your particular situation I don't see any catastrophic consequences of showing it too early (I'm assuming common sense when showing an unfinished unit).What does your gut tell you to do?

To get the replacement cost, your insurance agent should plug it into their modeling system which will incorporate square footage, catastrophe risk, etc.

I think at some point you can never have enough insurance in the event there is a catastrophic event on one of your properties.  

As if every quarter was going to have some new worldwide catastrophe that was going to force everyone to use Zoom.Same story with Airbnb (and all the rest). 

As far as I'm concerned, it's by far the more important thing I've ever written when it comes to real estate investing:CONTROLLING YOUR REAL ESTATE DEALS AND MANAGING CATASTROPHES

Smart rental property owners track every dollar coming in and out, and they know to have reserves in case something catastrophic happens.

It's important to know that the insurance industry is moving towards covering catastrophic events only.  

If you now have to go out and get private insurance, yes that's a negative, but high-deductible "catastrophic" policies are very inexpensive (i.e. a straight $5K to 10K deductible, paying 100% above that) Unfortunately (or fortunately?)

You need to confirm if it covers items studs-in coverage or if it will replace the entire construction of the apartment in case of a catastrophic incident like a fire.