Windows on external disk, can I reduced the size of the partition?

I allocate to much space for my Windows Machines on an external disk.

1 Can I reduce the partition without problems? (Mountain Lion)

2 I dont, but what happen to the partition on an external disk if you use Snapshots, I think I see somewhere that if you use Snapshots you cannot resize the partitions where the virtual machine is?

True ?

3 Can you delete the Snapshot and resize?

Thanks in advance....