Great read Dallas. Glad you decided against litter any place near the toilet. Someplace on here is a post about opening up the space under the steps going up to the bedroom to create a cat bathroom of sorts. Accessable from the basement for quick litter maintanance.

A few other things come to mind....
Hard to believe that only one cat was adopted

Have you ever considered CBD oil for the neurotic pup. Everyone is always amazed at the difference CBD has made in our Aussie, Koda.
It took his fear aggression down about 50 notches and he now even walks up to strangers on his own to get pet .