Ello and thanks for the guide first of all :3

I'm still fairly new to crafting so this'll help a lot. I still have two questions though and would be glad, if those could be answer @@

1. Which of the avaialable cross-class skills should I actually cross class? I'm kinda lost on this one since I don't really know, which I should use of those and which I shouldn't
2. I only recently managed to get my first crafter to 70 and bought a set of ilvl 290 hq crafted crafting gear (left side) as well as the MH/OH tools for that crafter. I'd like to know, how I need to meld that gear or if it's even necessary that I have to meld it, since I'm kinda confused what I should actually meld for those pieces @@

Thanks in advance :3