What you're saying makes sense, justremember that the window units create gobs of condensation.

Wayne just condensed my entire post into two lines.  

Check walls for condensation and mildew.

I'm replacing them because I see condensation on some of them and cracks in some of them.  

If you use your 4k for a DP, then where will the 2k or 3k come from to replace the condenser, furnace, or repairs after a tenant's damage exceeds their deposit? 

. $150 Run electric for condensation pipe in basement $120 Run drain line from condendation pump into waste water drain, $70 Replace all attic duct with flexible insulated duct. $6 per linear foot Mortar interior section of chimney inside of attic $400 Mortar exterior section of chimney $600 secure all loose electrical wiring in basement $85 Tearoff and replace south side of main roof, $4400 Additional cost may apply if board replacement is needed due to rotting or broken boards.No quote on the foundation yet.

AC replacement around me is about $1600 for an A-coil and condenser unit installed.

This allows for scaling growth and condensing ownership. 

This would be far more effective than your somewhat remote pond liner install as it would also ensure complete moisture protection from bathroom condensation.

I would assume that all the hvac condensers and anything made of precious metals both outside as well as inside the buildings have been stolen.