Hi Ian,
Was Trend Micro loaded and running when you installed Office and\or went through the first-run of Outlook?
I ask because I have seen issues before where an anti-virus program was running during the install of Outlook and it resulted in Outlook "needing" the AV app from there on out.
I would suggest running a Repair of Office, first. If the Repair runs successfully, hopefully Outlook will launch without error.
If Repair fails to resolve the issue, I would suggest doing a complete removal of Office. Once Office has been removed, disable any anti-virus you may have running and then reinstall Office.
Additionally, if you want to try and troubleshoot the CLSID error you're getting, I'd start with getting a Process Monitor trace while you attempt to open Outlook.
Once you have the PML, I'd start by adding a filter for path contains {7ED1E9B1-CB57-4FA0-84E8-FAE653FE8E6B}
See if that will help. My thoughts are that that CLSID is part of the no longer present Trend Micro. So you'll probably see Outlook trying to find it and returning NOT FOUND, which could result in the error you're seeing.
Anyways, I hope that helps!
Jahawk MSFT