Jack-Nader wrote...
The "Mage" line of spells has no real use. I would agree with the OP and say Don't bother 
Arcane bolt is a straight damage spell with no standout special effects. It gets resisted alot and it has a slow flight speed. Offensive mages need to maximize the amount of units they damage with any given cast and there are far better ways to do this than by spaming arcane bolt.
However, it's also a CHEAP attack manawise, and fills the gaps in straight damage nicely while other spells are on cooldown. It is the one straight damage spell you can use continuously without going OOM or having to use one lyrium potion after another, it's cheap enough to always be able to squeeze it in instead of doing nothing, waiting for your other cooldowns to expire.
Arcane shield is a spell that mages never need. It only bumps your defense up to the level of a warrior. "Glyph of repulsion" is a far more usefull spell and is vastly superior in damage mitigation.
Arcane Shield is targeted onyourself, while the Glyph is targetted on an area, so moving your mage is out of question if you want to benefit from your glyph. The glyph also doesn't affect missile damage, and costs more mana to activate than the shield, though the shield is a sustained buff, so those 30 mana won't become available again.
Staff focus increases your staff weapon damage by 1/3rd however if your in a position where you are routinely using a staff you are doing something very wrong.
It depends on the situation, but while fighting bosses, hell yes I use staff. Especially in a 3-mage party, I'm not interrested in bringing tons of lyrium potions, nor in watchng my mages do absolutely nothing because their spells are all on cooldown.
Arcane Mastery gives a spellpower bonus of 5. A 4th tier talent that only increase spellpower by 5???
Yes, but you get that spellpower for a talent, not from attribute points or gear. And this talent affects the damage and healing output of EVERY other spell you learn. It's basically a level and a half extra spellpower. If I wished to not use my attribute points for magic, but for constitution, cunning or dexterity instead, then here I gained some freedom for my attributepoints through using my talents.
And to finish all this: I'm working on my achievements for magic schools. Yes, I know there is a mod to CHEAT my way into those, but I find that utterly lame and feel there is absolutely no achievement in that, so I do it manually, by doing more than 1 playthrough. The Mage talents and spells give me just that "bit of everything" to balance out the weak sides of the seperate schools, and keep a versatile and useful character.
So overall, the Mage talents are definitely useful, especially if you're focussing on schools and want to play more or less cheat free.