I stumbled across a trick for that by accident. Sucked for me, but it might help you. Install Trillian on your desktop. Add your Google account, and then put all the unwanted contacts in one group. Delete the group. Google will treat this as you removing them from chat but not from your address book, so they’ll disappear.

I use Reader constantly, but I don’t think I’ve ever used the share options.

As for Priority Inbox, I mostly use it as a way to organize my Inbox as a to-do list. Anything requiring immediate action gets a star, everything else goes at the bottom, and the top section is generally empty. Which is great in the new setup, since I can set that top section to show all unread messages instead of unread and important ones, and empty sections disappear to save space.