Any precedent for these? Spells to increase fatigue levels?
Also, Lifeboost magic states that you can spend more fatigue then you possess to boost a spell... but don't you simply drop unconscious when you run out fatigue? So you would use up all your fatigue, take a bit of damage, and drop unconscious for example? really?
In a dramatic situation, I'd allow the magus to lose consciousness right after the spell takes effect (and being unconscious only ends concentration spells).
As for items granting extra fatigue:
Use the spell Gift of Vigor (ArM5 vanilla, ReCo), put it in an item and give the item to a grog. That way you can use your grogs as "fatigue batteries". You get fatigued, they take your fatigue.
For the record, this is contested. There's a thread somewhere discussing that very issue.
But there is nothing actually granting you extra levels of fatigue right? Other than shapechanging into a bear? ;p
With some bjornaer mystery, you can gain animal qualities. Some of them grant you extra fatigue levels.
Hi,
These are specifically prohibited, due to the Limit of Energy.
Yes. The normal rules about fatigue and spellcasting are specific too, that the spell takes effect before fatigue is lost. Since the fatigue loss occurs after the spell takes place, the overflow and injury also happens later.
All of this is straightforward, yet probably has enjoyed its time in the sun.
Anyway,
Ken
Hi,
Or a wolf, or a boar... Or by becoming an immortal magus and then acquiring the Extra Fatigue Quality as many times as you want it.
Replenishing fatigue doesn't need to be difficult. Sure, a magus cannot cast The Gift of Vigor on himself, but another magus can cast it on him. Better still, enchant it into the familiar bond and let the familiar cast it on the magus!
Anyway,
Ken
Good one, and a very good reason to have a familiar 
Hi,
Oh yeah; familiars are awesome. Bjornaer have access to some nifty Mysteries, but I consider their Outer Mystery to be a net flaw.
Favorite things about familiars:
Enchant long-term, constant effects into the bond. These do not Warp the magus!
Free Cautious Sorcerer
Either enchant Gift of Vigor into the bond, or go with a Spirit Familiar, who can use Might points to boost your spellcasting! (Note that you can spend a fatigue to grant the spirit temporary Might points with which to do this.)
Cool familiar powers that might be non-Hermetic
Lab assistant--maybe. (A familiar with Int -2 and no Magic Theory is not likely to be useful....)
Have a focus that applies to binding your familiar--which then also applies to any effect enchanted into the bond.
Extra set of eyes and ears (and nose).
Anyway,
Ken