AFAIK the TCM replay issue you're describing (something is created and dropped during replay, fails if can't create) applies to custom types and a few other things, and one way around it is CMS snapshotting so replay doesn't start at epoch 0; it wouldn't be safe to remove the trigger from the classpath until the trigger drop epoch has been included in a snapshot: https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-21%3A+Transactional+Cluster+Metadata#CEP21:TransactionalClusterMetadata-SnapshottingMetadataLog
I also think it's reasonable to not include triggers (or other custom fields) in the clone, but if users need to sort out what parts of their original table were copied to their clone it's not as convenient to have a separate command for it.
