Gave up for the time being. Uninstalled 2017 and went back to the 2015 version until I have time to diagnose. I realized it’s been an issue since the 2017 version came out, but has just gotten worse since last weeks CC update (expanded to more things being twitchy. At first it was just the character selection dropdown kept closing back up before I could select a typeface).

Well, after I got it open, I did a “save as” to get it into the latest version and THAT file takes massive amounts of time to open as well. Started an export to IDML to clear out whatever the issue it and it took a long time, during which there was a power outage in the building! Just got it open again (took 45 min). All I want are the master pages, fingers crossed I can get what I need before the next crash!
Suitcase Fusion seems to be behaving very strangely as well, not sure if it’s a font activation issue causing all the trouble.

OK, so I figured out a solution, I made a new master based on “none” with nothing on it and applied that to my page that needed changed and InDesign didn't crash.