@Barl
Honestly don't recall which difficulty it would have been and could have dropped from Flamespike's crew. Besides I thought uniques could drop from anyone anything anywhere. Would swear I've had a Soj drop from a Shaman/Fallen - die so fast hard to tell which - during Gem shrine running between Rogue Camp and Stony Field [again difficulty uncertain]
@Excalibur Didn't see any mention of your Cold Mastery pts?
For an Orb build my aim is 20 pts in both Orb and Cold Mastery iirc by Level 46-ish?
With regards to Maxing Static and Warmth allocate points based on how close you want to stand to opposition [Static] and Mana+Refresh your set-up provides [Warmth]
My Sorc can continuously spam (low lvl) FB, or GS, and still replenish Mana for the next Orb. Notwithstanding gear requirements (STR 80 Goldskin DEX 51 S/Shard) all other skill points going into Vitality.
While there's no item level requirement to equip gear my understanding/experience is that it does factor into gambling where for best results one needs to be within cooee of the item level. With two exceptions all my Sorcs gear is gambled.
Hotspur (5) Nightsmoke (20) Magefist (23) Spectral (25) Goldskin (28) and Soj (1 but at 50K a lot later) plus Rare Amulet "Beast Wing" + Ring "Viper Grasp" - as mentioned earlier post.
[Gull (4) Chance (15) Frosties (29) in stash]
Exceptions, for want of anything better - P/Diamond Shield (P/gem stats can vary) and P/Sapp x24's Crown (48 Mana) - Act2 (N) Fara for 3os shields and forget who sell 2os Crowns?
Having said all that it's not to say I've not tried either a full Iratha's Build nor a full 5x +1 skill build. (Tarn, Culwen's Sigon's, Mage, and Silks)
Edit spelling/grammer and just wanted to add IMO - Best NPC = Fara for One-stop Heal and Repair with Stash and Cane nearby.
Edit2 Rares will change their names Fwdd to v1.07 but afixes will remain the same.