Hmm well the only magical bracers I've found so far had stat requirements. Maybe next time... GRR
Regarding staffs:
It's about the way spells work. Staff damage doesn't improve your spelldamage but the damage values on your melee and ranged weapons do improve damage of maa / marksmen /scoundrel skills.
Plus isn't it technically possible to find a two-handed sword with +3 int as well?
If so then the only actual benefits for mages wielding staffs as opposed to any other weapon is that there is a crafting recipe for +int staffs.
The damage on a staff does impact mages. You can melee with a staff, for example (perfectly acceptable to do if your mage's spells are on cooldown and the risk is minimal (e.g. target is knocked down or blind)). The damage on the staff also modifies your Staff of Magus ability (located in the "special" tab of your skill list).
As for your comment on bracers, I honestly can't remember the last time I saw a bracer with a STR or DEX requirement.
