My second problem seems to have been resolved - it is now picking up email addresses that are not in my Address Book.
But the second problem is a message from Outlook Express and not from Outlook. The link you suggested says this fix doesn't operate in Outlook Express. But I have gone into Tools, Options, Security in Outlook Express and have unticked the 'Warn me when other applications try to send mail as me' box but I'm still getting the boxes asking for confirmation that I want to send each email. Is there anything else I need to do?