IE if you patch the drywall, 3-6 months later you will have drywall cracks again if you dont get the underlying foundation fixed, and begin to maintain the moisture levels around the house.6)Almost all old houses will have current or past issues with termites.

Over time the wood is going to expand and contract with changing temperature / moisture levels and eventually will begin to bow outward and fail.

Should any moisture barrier have been installed?

This tool pointed out areas inside drywall that have had moisture issues.

Negotiate with your tenants to either allow you to show the property while they are still in it, even better have them do the showings, and upon finding an ACCEPTABLE replacement tenant, you will let them out of their lease early.If you "sell" this to them gently it's a great solution. 

When the sealer fails moisture will absorb in causing stains and allowing for possible mold/mildew growth.

But my dad who had gently nudged me into what at times felt like a ridiculous endeavor was also super conservative financially and convinced me to finance it on a 15 year loan.

This will let you know if there are any plumbing leaks or any clogs in the sewer lines.2nd look at the foundation very closely, look for any stress cracks and see if any moisture coming in.3rd check out the HVAC systems.

Thanks for posting this.Aloha Berry, thanks for your gentle input...Just to be clear, I absolutely do perform my Own Due Diligence on every property every time.

BTW the joists look good but a lot of the subflooring has been ruined by the moisture.