1. SNMP is used to read and write the vlan info on the switches.
2. You can use port profiles or NAC roles to set destination vlans. An example of how Port profiles would be used is if you want a port to start in a desired authentication vlan and transition to a specific access vlan afetr posture assessment and authentication. NAC roles can be used to assign ports to a specific auth vlan based on things like credentials....
Hope this helps.
Ern