Query around Masking Views in VMAX

Hello,

I recently started exploring the symmetrix array in our center. I have following few queries around EMC VMAX array Maskking views.

In VMAX we create 3 groups, initiator, target and device group. Combinig the 3 groups we create a masking view. Which automatically some how masks the devices in the group to hosts.

Now,

1.  Is it necessary for devices/volumes to be mapped to Target ports(Director ports) in advance? as we used to do in previous Symmetrix arrays.

2, Is there a case where a initiator port will be member of muliple Initiator Groups? Also is it valid to a Initiator port being member of multiple masking views?

3. From where one should consider lun unamsking/maksing? What should be the starting criteria? I mean what should e the identifying criteria for Target ports?

Thanks,
Pranav