Off the top of my head, one function I use a lot in Outlook, that's now hidden, is the ability to edit someone else's email
Well, you can always add it to the quick launch bar, or in the case of Office 2010, customize the ribbon to add it.
I'd say it's missing by default because almost nobody really uses it. For most people, if they want to edit a message, they're forwarding it, and the message becomes editable when forwarding. Yeah, there's a lot of people who use some oddball tools a lot, but unfortunately just because you use it a lot doesn't mean it's a popular with other people.
Microsoft can't put every feature possible on the screen - that makes everything cluttered and just adds to the feeling of complexity to office. So, yeah, they do have to decide what get put in the home tab, what gets put in a different tab, what goes into some sort of context sensitive menu, and what goes into the "command well" - the list of commands that are available to be added to the Quick Access toolbar (and to the ribbon in 2010).
Sorry that the defaults aren't your favorites. It's very hard for any company to create defaults that please everybody.
If you absolutely can't find something, it's always available to be added to the Quick Access toolbar. You don't need to dig beyond that.
Once you place it on the Quick Access toolbar, it'll stay there always. So it's basically a one time issue IMO.
If you have a layout you like, in Office 2010 you can export/import the setup easily so you can copy it to other computers.
I don't know about anyone else but I find that the icons are kinda visually distracting.
I think that's a matter of opinion, though. I'm a very visual person, and IMO icons make commands instantly recognizable rather than having to read every single line of text in a menu. Microsoft has put a lot of work into the tooltips, though. Every command should have a tooltip, and in the Quick Access customization, all of them should have labels.
Sorry that your favorites weren't the ones Microsoft decided to keep in the ribbon. Rest assured, however, they're likely all to be in the Quick Access toolbar customization, and in the ribbon customization in 2010.