Wow...
First of all, gSpike does not synergize Ice blast damage (it increases freeze length). Ice blast is the main spam skill of a blizzard sorc because of it's damage (can get up to 10k with damage gear on, enough to 2 hit people).
Also, orb is FANTASTIC at taking the last life points off a dueler who survived a few beatings. Also, it has uses to kill BM mercs before they get a chance to attack. Orb is definitely worth the one point.
BLIZZ SORCS SKILLS RARELY CHANGE:
20 blizz
20 ice blast
those are a given.
20 cold mastery
20 ice bolt
rest into glacial
1 point in orb is optional, but VERY RECOMMENDED.