Re: "if the shit does hit the fan"
"Office 2016 where reinstallation following some hiccup takes hours, followed by the hoops required to convince MS that you are entitled to perform the reinstallation and activate the software"
Actually had to do that twice this week. Both times took around 10 minutes from start to finish. This was the complete reinstall/repair option. All sorted.
Something might be wrong at your end.