And overruns on construction plus potentially extended time on the market and/or price reductions in a softening market?

Instead of negotiating a price reduction, negotiate the Seller to buy down your interest rate.

Number of price reductions ?

Based on the context of your chapter dealing with the Snowball Plan - for the purpose of debt reduction - I would think recasting could have been included. 

How much in potential rent and principal reduction of the mortgage are you giving up during the waiting time?

Additionally, the actual reduction in rate received by paying a discount point per Bankrate is about .25%.

I hope your place sells for 260k, there no wiggle room for price reductions, buyers asking for concessions, etc. 

Loan Fee Rates for Loans Closing On or After April 7, 2023 and prior to November 14,2031VA Purchase or Construction LoansDown Payment Amount Funding Fee PercentageFirst Use Less than 5% 2.15%5% or more 1.5%10% or more 1.25%Subsequent Use Less than 5% 3.3%5% or more 1.5%10% or more 1.25%VA Cash-Out RefinanceFunding Fee PercentageFirst Use 2.15%Subsequent Use 3.3%Other VA Home Loan TypesLoan Type Funding Fee PercentageInterest Rate Reduction Refinance Loan (IRRRLs) 0.5%Manufactured Home Loans (not permanently affixed) 1%Loan Assumptions 0.5%Native American Direct Loan (Non-IRRRL) 1.25%Note: Reduced funding fee rates apply to loans made to purchase or construct a dwelling with aDownpayment of five percent or more of the purchase price.

You could easily find yourself in a place where a loan today at 5% has a lower monthly payment than a loan in 5 years (with the associated principal reduction) at 7.5%. 

And that 25% reduction causes the rent income (usually) to be negative - but at least it would still be lot better than not being counted at all. 2.