You only need 4 of the providers running, Internet Mail (for OE6), Instant Messaging for messaging, P2P shield if you use file sharing (I forgot to ask) and Standard Shield for on-access protection.
You do not need Outlook\Exchange and can remove it, add remove programs, avast, click change/remove, select change. Then untick the Outlook/Exchange box, next until you are done and you won't see it anymore.