In the account settings for your MSN account, you should be able to check the option to sync mail.
Likewise, in Gmail account settings, you should be able to change the sync frequency to "never".
As far as the calendar, I'll poke around, but I'm unsure because I don't really use the calendar except for the occasional quick reminder.
Edit:
When I go to create a new calendar event, it shows the account at the top of the screen. On that same ribbon, there's a color palette button that let's me choose a color.