I think that conversion in class features should be a niche that belongs to the transmuter and to him only. Thats my opinion at least.
I think this is the strongest argument I've seen against the "free CP wizard". This is already the Transmuter's niche, and he's a little narrow as it is.
Hmmm... maybe it's a little weird, but I've got a suggestion for the wizard: every time you cast a spell, each of the glyphs in the wizard's inventory has its mana cost reduced by 1 (minimum 0). When you cast the glyph, its mana cost resets.
Imagine a wizard with BYSSEPS, HALPMEH, BURNDAYRAZ, and WEYTWUT in his inventory:
BURNDAYRAZ (6 mana, -1 to all other glyphs)
BURNDAYRAZ (6 mana, -1 to all other glyphs)
BYSSEPS (0 mana, -1 to all other glyphs)
BURNDAYRAZ (5 mana, -1 to all other glyphs)
HALPMEH (1 mana, -1 to all other glyphs)
BYSSEPS (0 mana, -1 to all other glyphs)
WEYTWUT (2 mana, -1 to all other glyphs)
BURNDAYRAZ (3 mana, -1 to all other glyphs)
So long as the wizard rotates his spellcasting he can get enormous discounts, but he gets little benefit from just spamming BURNDAYRAZ. This might be one way to turn him into the utility monkey he seems to be envisioned as without just overbuffing his fireball or PISORF attack. In the above example, the wizard saved 18 mana on 8 spells, but he can only get such a big advantage by mixing up many different glyphs.