Your focus at all times should be caster levels, spellpower and dc combined.
What suplements lack of spellpoints can be changed by going more spellpower.
You want challenge items from 3 and til cap as they offer the most benefit spellpower wise, you want the event stick for lv 5 that gives most fire spellpower and acid spellpower at level, you want to abuse duality robe and abi set for even higher spell caster levels, you want clickies, sp discount clickies, all you can find, you want the dodge and spell crit damage clickies.
Abbot, cove, mabar all offer irreplacable items that make the journy much faster.
You dont need to swing a axe, ever, not once, if you do it it is only if you dip into eldritch for the 30 spellpower.

You want spellcraft items, custom crafted at higher levels, you want spellpower points, you want dc gear, you want ravenloft spellpower set.
You need a better selection of spells, (actually helpless is useful in heroic, single target hold, sonic blast, hypno all help to make more space from reapers).

Wings at lv 12 is the single best defensive tool we have as sorcs in heroic content.

All depends on skulls you run quests on, but from doing 6 lifes in row as sorc im pretty confident that sorc can effectively run 7 8 skulls on most quests from mid levels, up til then its a mix between 4 and 5 skulls and early levels 3 skulls-4skulls.
For r1 runs, sorc beats warlock in all possible ways, to do it that way, get sp boost wings and nuke away.

Issue is that you need to select quests you run, as it is not a allrounder like wlock.
It lacks the temp hp, but with enough focus on spellpower it can do some quests faster. (boss fights with no charm is where sorc excels at)

Also why dont i see anyone suggest a gsteel sp int skills item in this thread?
Imho its mandatory on a sorc