But this is because the people advising me know that I have history in construction and I can spot major issues in the foundation and structure or if the house has a moisture problem.

I agree that it seems excessive. 

I would imagine that in the end, there are often times small sections of land that they can't use and that a typical home builder wouldn't want... what is the name/ term for this excess land? 

So I was listening to a podcast yesterday and I heard someone mention that when you borrow for loans in excess of 4 mortgages, lenders require 6 months cash reserves for the sum of all mortgage payments.  

Furthermore, it would allow me to use excess cash flow to keep acquiring more properties and or de-lever myself.

Upon initial purchase I hoped to rehab in 30 days (in hindsight that wasn't realistic anyway) but once we determined we could dig down and finish the basement, I slightly changed up the project and with excess time for other things.. it took 11 weeks total (which other flippers in my area says is more appropriate, if not on the faster side of flips of this caliber)--Networking is important as we all know --> don't forget to utilize your resources. 

Water was leaking and Foyer light Dome was full of water and leaking from there as well. because of excessive water drips, dry wall near the floor was also damaged.I went under contract for this property with an escalation clause as this was in great condition and paying 3% over what I had initially put in before the counter.

Operating expenses also include advertising, management (even if you do it), entity maintenance, legal fees, evictions, court costs, damage done by tenants (in excess of the deposit), utilities paid by the owner (at least during vacancies), capital expenses (not technically an operating expense), etc (I could go on and on).

Continue as is, refi and buy more, use the equity as collateral for your 20% and buy more with nominal out of pocket cash, take some of your excess cash and make short term high interests hard money loans, cash out and go buy an island in the caribbean, etc.

Many lender get timid when it comes to cashing you out at a level in excess of your basis - but if you've owned the deal for 5-10 years this should be a non issue.