Any glaze could have a "poor fit". The opposite of crazing is "shivering". If the solid glaze does not shrink as much as the pot does, then pieces of glaze can pop off, or the pot can be ripped apart. I have only had this happen, thankfully, with experimental glazes- never with a celadon.
There are a lot of different kinds of celadon, as have been discussed here- some are glossy, matte, fish scaled, pale blue, gray, green, etc etc. I tend to stick with only iron as a colorant. My main celadon only works in the hot part of the kiln, it likes to be applied somewhat thick, and it develops lots of tiny bubbles in the glaze that give a great effect (not surface bubbles, more like they are trapped in the glass).
I have been experimenting with a red clay that I picked up in SC when I was there on business (in Edgefield, which has an amazing antebellum pottery history). I've been able to get colors ranging from deep almost copper green, to celadon, to tenmoku (black, breaking to rust color in thin spots) with simple clay/woodstove ash/feldspar combos. Some of these glazes give me wild electric blues that I did not expect. I was confused until a SC potter told me about the "rutile" mine and content in that local clay.