Hello,
To rename a VLAN you can simply use the JUNOS 'rename' command:
[edit vlans]
rename old-vlan to new-vlan
At this time, there is no range command for interfaces so you must add them to a VLAN one by one. This feature will possibly (probably?) be added in the future and this is indeed frustrating when configuring via cli - a "workaround" is to configure using the web interface.
Regards,
/david