You’re working with InDesign and looking to avoid orphans, widows, and runts, so you’ve got your keep options up and running for those first two and you have Brennen Reece’s article bookmarked so you can reference that GREP expression. Good job!
So you’ve got \s(?=\w+~S?[[:punct:]]$) running in your basic paragraph style keyed to a no break character style, cascading down through all those styles based on that, and all is good. That’s such a good bit of GREPiness. What it does is this:
“As long as there is a space followed by a word with at least one punctuation mark at the end of a paragraph, apply a certain style to the space.” In this case, a no break character style.