It's designed to be very similar. If you are already familiar with Word, you should feel right at home.

I’ve been using it for over a decade now and have only rarely come across broken documents due to proprietary features. If you’re making docs for yourself, I’d say it’s pretty much a 100% replacement. Things can get a bit more fucky if you’re having exchanges where you edit with Libre and someone else edits with Word. But other than that, they’re pretty darn close.

Pretty much. It was OpenOffice years ago, but then Oracle got involved and so all the devs left and put a new name on it.

No. That's the point. LibreOffice does not send your data to Microsoft.

LibreOffice is what Microsoft Office WAS without the bugs. If Word and Excel worked for you before the cloud, Libre is golden.