I believe that centering is most important because that determines the condition according to most catalogs. A well centered stamp means a grading of VF condition. Less centering means lower condition to F-VF, Fine or VG.
The perfs would be next for me because healthy perfs means a healthy stamp. Although minor damage such as short or blunted perfs may not harm the stamp that much. Too many faulty perfs will get a negative comment on a certificate or Auction Lot description and decrease the bid on the stamp whether it's
ebay or Feldman.
The cancel is last. Of course, if it is a very heavy cancel, then that's a negative. But for most postmarks, it may be light or average. There is no negative here but it is a positive if it is good postmark.
Something that most collectors don't look for is the possibility there's a variety on the stamp. This is something I always look for even before the centering. But that's only because that's most important to me and the fit into my collection. Because few collectors look for this, it gives me the opportunity to find more of them.


