crafting schools

Hi Community I have a couple of questions regarding crafting materials. Prolly both dumb , but going on the only dumb questions are those never asked ...... 1) The gear dismantler I have these legendary materials and I don't seem to be able to craft anything with the craft shops I have , nor...

I know Metal workilng is a given for the Celts, but sometimes it's hard to know for sure. I simply love that feature though, and would like to get better at using the right kind of crafting schools is best, since I ofthen have chosen the wrong ones (wrong ones regarding producing "usesless"...