IP address for a Layer 2 Switch can be assined only to the default VLAN (VLAN 1). The Ultimate goal behind assigning IP address to VLAN1 of a switch is to remotely control / configure the switch..
For Query 2
The Mac Address 0180.C200.0000 is a multicast MAC address and is the Destination Mac Address in the BPDU( Bridge Protocol Data Unit). The Source Mac Address of any BPDU will be the supervisory mac Address.
For Query 3
Please refer to this site.... I am not very confident with the answer