Re: few questions about craft/gamble
+2 to class skills is lvl 90 prefix (both circlets and amulets)... so you need to gamble/craft an item with ilvl 90+.
1.) Gambling: the ilvl of a gambled item is clvl (-5 to +4). This means you can gamble +2 skill circlet/amu since level 86, however 90+ level is optimal for gambling.
2.) Crafting
The ilvl of a Crafted Item is equal to half the level of the crafting character (rounded down) plus half the ilvl of the input item (rounded down).
Optimal level for crafting is 93, this guruantees you crafted item will allways have 90+ ilvl with gambled stuff (amus). You have to be at least level ** to get a chance to craft +2 skill amulet.