few comments on the support issues you mention;
- Groupwise cluster conversion from Netware to OES2 is supported. Many have done that.
- Running Groupwise on NSS with Long namespace is supported. Migrate, change all to lowercase and run on Linux.
other OES2 comments:
- the noatime can also be changed on the NSS settings level.
- remember to check that salvage is off for Groupwise volumes.
- on OES2 cluster, you might want to set up monitoring scripts to monitor your Groupwise service status.