1. 802.1Q.
2. 1, 4094.
3. Switch spoofing, double tagging.
4. 7.
5. It increases the number of possible VLANs (16,752,649 with a single level of nesting, with even more VLANs possible if there are multiple levels of nesting).
6. Increased throughput, redundancy.
7. None (we have to create rules to allow access from VLANs to other networks ourselves).
8. Trunk ports and VLAN ports.
9. PVID.
10. Static, Dynamic Trunking Protocol (DTP), VLAN Trunking Protocol (VTP).