Short answer = No.
As long as there is no changes to FDISR preboot, should be no problems reallocating some space.
Might be some specific tidying up depending on what your set-up is.
Be careful preserving old and allocating new drive/partition names/letters.
MAke sure u keep an eye on snapshot sizes and archive destination drive name.
In view of new partition sizes; might need to redo some snapshots and archives after changes to partition sizes.
Be wary of some defraggers if planning some extra tidying.
( cant recall which but some defrag tools have ..erm.. 'misplaced' snapshots)
Keep a fresh system Image j.i.c.
What tool are u thinking of using for Resize/Shrink ?
I have done similar many times with BING from Terabyte with no real problems.
HTH
OOI why Vista AND W7 ?
Regards.