First of all. I don't think we should discuss about how much XP we should put into crafting skills/spells. This issue should be calculated well before Crafting guild in. Otherwise, it will not fit its purpose.

In any calculation should be variables and constants :). So, the primary constant is which skills/spells should be in Crafting guild.

Suppose, one spent years and trained almost everything in crafting. So, with current list he will be able to rule MUD alone. I DO NOT think this was an original idea of that guild.

Let think on it in this way:

Those skills are in list with category (t - trade... why not crafting? \:\) )

1.Craft armour - forge amour from ingots, or fashion from leather
2.Craft weapon - forge weapon from ingots, or use carpentry
3.Make potions - brew potions
4.Scribe runes - inscribe runes armour/weapon, and at the rooms
5.Make enchantment - forts, puissance, accuracy, light
6,7,8...Common skills: detect magic, mark, survey

If ice and flame weapon would be allowed in 5. then corrupt, bless, vampiric should be there as well. And I would to see poison, singing, acid chant types too.

TW and TA shouldn't be in this guild. As well as dispel rune, pick/install lock, install trap, balance (because it adds nothing to wield % but equals puissance+accuracy).
As an option they should be very high level, and can't be allowed without specialization: Weaponsmith, Armour, Rogue...

To make things "harder" we may have some prereqs to complete crafting.
For example, to enchant weapon with fire you should stay at the forge, hold weapon and cast any "fire" spell at it. So, guild with no spells couldn't do enchants.
But this way means a lot of changes with primary skills, beacuse it will be hard to make all prereqs balanced now.

Regards,
-Guinness.