[Sandman]

What weaknesses does this race have?

I can see gold cost as being the major one, but that's about it.

Is it really necessary to have their mages be amongst the most powerful in the game? Their most basic mage is quite powerful already, and they have a staggering THREE top-tier mages.

How many other nations have access to lvl 3 (excluding holy) in three different magic paths, with NONE of those mages being capital only?
And the arcane changeling effectively gives them access to all paths of magic. Way, way too powerful.

At the very least, you should remove the astral mage. Having lvl 3 in astral is not 'a little astral' like you say in your first post. Fire and air is plenty, and astral mages are very common anyway.