hello alli have 3 questions please help me

1-while i want to run MSTP (maybe with VTP V3 or VTP V.2) must I config in all switches
(Both Layer 2 and Layer 3) as i show in picture scenario?i mean i should type commands:
spanning-tree mode mstspanning-tree mst confrevi ...name ...inst ....in all Switches ?NOTE: I run HSRP in SWITCHes(R1 and R3) and Link Aggregation between All Switches Layer 32-Does or better to ask Can 
MSTP Preventing Loop in Below scenario that i put picture and show in it?3-for 
access to Client(
C1 that connect to SW4 in end of picture :in
 red square)which ip shoud be Set for 
Default Gateway ?Define Gateway in SW4 by : ip Default Gateway or int vlan ...ip addressand use int Vlan Add for C1 gatewayORwe should set ip of Router 5 (R5) for DG?
thanks a lot