Alex,
Your points are fair when discussing already existing documents and viewing them (after created in Office) in Google Docs. True, some formatting may be off.
As a developer (and consultant to many regarding such topics), I would say that the points are moot when considering the fact that those who have already created the documents more than likely already own a licensed (hopefully...) copy of Office.
With the availability of Google Docs, I have been able to ride my 2003 version of Office to infinite and beyond, using it only to open already existing files. Anything that is new can be created in Google Docs, and therefore any upgrade in my MS Office suite is unnecessary. I already own software to open my own files, and Google provides software to create new files (not to mention the cloud storage I can get with Google).
The way I look at it, Google was dead on when it said that Google Docs supplements office nicely. This is what I tell people who have me purchase and set up their computers for them, and why I can usually save people $100 or so on the price of their laptops. I would say that a business that deals heavily in lots of graphical additions to documents does need Office (Open Office works just fine too. We use it here on our Linux network, and have never had a problem). But I would say that 90% of homes, and probably 50% of businesses would do just fine with the formatting allowed by a Google Document.
I don't see the reason for buying MS Office anymore. There are just too many other options that are just as good (if not better), notably Google Docs and Open Office.