Sounds like if I'm going to start a new FC campaign before Spellbound comes out, maybe I should get the channeler and just use that class in the game in place of the mage? It would prevent the wide range of power for the normal mage at high level?
While I support you getting the Channeler (excellent class, extra spells that largely work in FC and more money to the Crafty crew), I'd say a new Sorcery Campaign Quality would help with a lot of your problems:Aspected Magic (Perminant):
Any character who gains Subtle and Quick to Anger
must immediately pick one School of Magic. Whenever the character gains spells known, they may only be selected from the School of Magic chosen.
That way the group isn't limited to just the School of the Chaneller, and it's Energy, Force, and Weather spells, but still avoid the mages ability to solve any problem at higher levels. The Chaneller is an excellent class (as are the Seer, Conjurer and Reaper), but having just one class like that removes a whole chunk of available spells entirely (and players will often know all spells that currently exist for the school by about 6th level).
I think something like the above will work better as a stop gap solution, especially if you combine them - allow Chaneller / Conjurer / Reaper / Seer and have aspected magic for the other schools for the next couple months. Also of note, the Chaneller is as different from the Mage as the Captain is from the Soldier - it's definitely not just a case of swapping spell lists (with just it all magic users in your campaign take on an entirely different flavour text - just something to be aware of).