You do have a lot of variety in NH ranging from lake rentals, to foliage locations, to snowmobile and ski accomodations. 

I'm struggling finding a multi family home in a decent price range of $150-200k in Leander or north Austin, TX area.

Tenants can range from very good executives at Abbotts & officers at Great Lakes to some of the sketchiest tenants.  

The houses are 2010+, the market value is somewhere 230K-250K, the appraised value includes 40K+ land, and new houses are built close by for the same 230-250K range....why would the replacement cost be 340K? 

If we decide to sell the property, we would list it in the range of $400,000 to $420,000.

My CPA says it is sufficient for tax purposes to have records of invoices from the PM to me. 

I have equity in my duplex that I would like to leverage, but the interest rate on the mortgage is at 2.7% so I don't want to cash out refinance (considering interest rates right now are in the 6-8% range).

This alone MAY be sufficient for you partner to believe that you will NOT “do nothing” and he may at this point reach out to you.2.

The cost of adding a bathroom typically ranges from $25,000 to $60,000 for a full bath, or $6,000 to $12,000 for a half bath.

Seems perhaps a little low -only say this because my 4bed in Arvada CO is about $290/mo and with the Boulder/Louisville fires a few years ago a lot of insurance has gone up like crazy in the front range.