This looks good to me. Search will not be automatically upgraded.
I'm also not sure PEA file will be copied by SMW, but if you know where the partition expects the fle, you can copy that to the new servers manually (same location). PEA file only has aceesrights etc, not he 'originating server', so that should work without issues.
A few comments:
1. You can configure MSMQ on the target before the migration date - there is no dependency on the existing MSMQ disks or its contents. Also I've seen weird issues with security on MSMQ folders migrated from other servers, I'd just go with a fresh set of disks for MSMQ.
2. Centera PEA files should be copied separately, you can copy them in advance as they don't change
In emergency rollback you are missing the step to reattach all disks with data back to old systems.