Battle mage guide

So without a doubt, blue is a must?

Up to you. I'm just pointing out all the things you miss without it.

3rd job build: SO MANY GOOD 1-POINT SKILLS

70: 1 Tele Mastery, 1 Adv Dark Chain, 1 Death Blow
71: 1 Battle Mastery, 1 Super Body, 1 Conversion (in case you need a big temporary HP boost for something)
1 Dark Shock
Max Battle Mastery
Max Death Blow
Max Tele Mastery
Max Dark Shock
Max Adv Dark Chain
Max Super Body
Max Conversion
Max Adv Blue Aura
Rest in Reaper

Explanation: All of these skills have amazing utility at level 1. Anyone who's ever played a post-BB 3+ job mage knows how amazing Tele Mastery is and how great of a 1-pointer it is. Adv Dark Chain increases your Dark Chain range by a ton, and obviously that first point in Death Blow helps up your damage by a lot.
Next you'll want that first point in Battle Mastery for +11% damage, and 1 Super Body for the extra +1 attack speed 1/3 of the time and 1 Conversion; in case you go somewhere and you need +64% HP for 1 point, it's there.
Battle Mastery is the biggest damage booster, so that's maxed first. Next is Death Blow, and then Tele Mastery. After that the build is kind of fuzzy, really depends on what you want.