Some owners are asking for prices in the excess of $1m and I wouldn't be surprised if they received close to ask.

If you go with the slightly under calc A/C unit, the compressor/condenser will run longer thus removing more moisture in your conditioned space.

Either a dry-lok type product if moisture is an issue or regular paint suitable for concrete.The flooring is something I am running into problems with.  

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.

I agree with Chris - put in all the numbers, save for all expenses, be conservative, and expect to SAVE (not use) all of your excess cash flow.

Can I charge her for having to patch and re-paint due to the damage caused by the excessive amount of holes in the wall?  

Much cheaper than a chimney cap that still allows moisture & wind infiltration.

Some people would rather own their properties free and clear which is totally fine.You can take the snowball approach like you are talking about and use excess cashflow to pay down debt.Besides the obvious advantages of keeping properties leveraged, I think the only thing you are missing here is once you pay extra principal, that $$ becomes illiquid until you either refinance or sell.There are always pros/cons to every method you just need to choose what's best for you

You'll need to design your landscaping and parking lot to collect this water and more than likely run it underground since you don't have a lot of excess land available to construct retention ponds. 

The bank does not get to keep excess funds.Since it has been this route a few times, there is a possibility that this is an auction by the bankruptcy curt.