There is short-term savings in replacing my mortgage with my credit line.

Use your savings and equity to get the next one and keep this one. 100% agreed here. 

I kept quite a few, but would be retired had I kept them all. :(  

A good HI will go over your house with a fine-toothed comb.If you can find an Ex (or Retired) HI that is also Certified, that would be even better, since they will understand the structure/electrical/plumbing systems in more detail than a regular HI...

How much time are you saving by doing things more digitally and with more automation?

In high property tax, high insurance states like Texas, you may see $20,000 in cash to close while you are saving $250 a month to refi.

I think you would save a little while rehabbing, but at what long term cost. 

Then after that is achieved, we will begin saving for a down payment on our first house that we plan to buy in the next 2-4 years.

We still own this property, but we have: 1) leased to market rent, 2) successfully implemented RUBS to save roughly $3,000/year, 3) Reduced vacancy/bad debt from pre-acquisition T-12 of 15% to less than 4%.

@Witty WordenIt can be a scary prospect to take a risk with a large amount of your savings.