Re: The beginning of the end
On balance, I now prefer LO. Your mileage appears to differ, of course - if you're frequently use a Word specific function it makes sense to stay with Word. That is, until Microsoft decides they need to change the UI again, of course :).
I would have stayed with Word and Win7 but MS in their wisdom decided otherwise ;-)
The menus the stupid ribbon replaced can be returned with an add-in that works quite well. [Aside] Sometimes Outlook hangs on startup and this is caused by it failing to load the Menus add-in.[/Aside] However, your comments inspired me to do some investigating, something that's always tempting when you really should be working on the document! It would seem that the Organon add-in for Writer might do the trick.
I too have worked with Word for a very long time (as well as Word Perfect, Lotus Word Pro and Wordstar) and IIRC there was no autosave in Winword 2. My autosave is Ctrl-S and it's completely automatic. That said, I've never had a problem with Autosave. Mind you, I've always turned off Quick saving. This latter saves edits to the end of the file rather than in place and makes for a longer, more complex file.
Your theory as to the cause of instability seems sound, but I invariably paste as plain text. Local formatting is pretty much confined to bold and italic. Another cause of headaches in Word is attempting to use it as a page layout program. It's not and both Word Perfect and WordPro suffered from the same blight of adding such features.
Yes, Shift-F5 is a dandy feature. Another workaround is to insert some unlikely text (e.g. "^6") before leaving the document. Then you can Ctrl-F to find it when re-opening the document. Since it's already highlighted, you can just hit the Del key before commencing work. Your two window solution seems more cumbersome.