Here ya go.
1. View --> Show Offline Contacts
2. Go to status and either set available or idle, whichever you want, and then use a script from Edit --> Insert Script, or if it's msn just go to preferences and under personal put one of the ITunes scripts in your name.
3. not possible, most people find it distracting and annoying.
4. Go to preferences then events
5. Go to preferences, then accounts, then your account, then under options check "check for new mail"