In previous versions, volume was expressed minus 2-0s,  now it appears that actual volume is being used.  (4 million shares as 4,000,000 vs 40000) .  If the actual volume is used, how does this affect older PCFs?  Do they need to be edited?

Yes, older Personal Criteria Formula which were imported from TC2000 version 7 check for the value of volume or average volume would need to be edited to check for the desired volume values in TC2000 version 12.3, but you need to leave them the way they are to use them in TC2000 version 7.