The PVC had literally cracked and broken under the strain....  

Where is the power supply/main panel? Is

:D )Exterior- Duct tape and plastic sheeting (temporary fix for cracked window panes)- Tarp, 2x4s, and nails?

I may reconsider in the future.Also, I took measures when I first acquired the property to make the units more efficient, such as installing dual-pane windows and coating the roofs with white reflective elastomeric paint, and in one unit I replaced an A/C with a swamp cooler. 

They usually "expect" special treatment and when things become strained, guaranteed they will, you will either become the black sheep of the family or be seriously taken advantage of at the expense of the trust.

The #2 face of the glass is on the exterior pane of glass located on the inside face.

Only strained logic would contend this is consumer friendly.  

There are 11 windows total, and they would be the double pane storm windows, all windows on the house are the same type of windows.

One has a wife and the other a girlfriend, that might put too much strain on both groups.

Anything I should look out for in particular (besides the obvious potential strain on the relationship).