Q – 1: Unfortunately only your 2007 users will see the color catagories outlook 2007 assigns, This is a limitation which cannot be resolved except by upgrading your outlook 2003 users to outlook 2007. Sorta like how you can’t get a 2008 model car in the 2009 model colors from the factory. Outlook 2007 is backwards compatible, but outlook 2003 is not, of course, “forward compatible” in that features added to outlook 2007 are still not going to be viewable in outlook 2003.
Q-2: You are also out of luck on the calendar. Drag and drop is your only option when posting to the shared calendar. Outlook and Exchange are useful tools, but unfortunately they do not do EVERYTHING we want them to.