Thats what I was thinking- there's simply no other ability as a sorc with that amount of damage, and I am definitely not changing to 2h at this point, although I did consider it for the critical strike and wrecking blow.

I was thinking of maybe using a lot of over time damage abilities. Thoughts?

Sorcs are all about timing, hit someone with mages wrath and curse, and frag them when the curse pops, they'll be at low health causing mages wrath to finish them off. Simples.

i think it's possible to build without it, but usually not a good idea. it's probably only viable if your want to run a very special build that needs many many skillslots to achieve it's greater goal.
if you use c-procs, you have a cheap+super strong ability with CC effect. only downside is that it's easy to dodge or block and can be reflected.

however, you don't have CC alternatives without those downsides. destructive clench can also be dodge/block/reflect'ed and the volatile familiar can be kited, especially (but not only) with roots. offensive streaks are really offensive moves. you leave your mines, you move into enemy territory, subsequent streaks are more expensive and shields may run out in the meantime. imho it's only worth it if you go for a kill, have allies around, or to set up a meteor.

on top of my head, i can't think of other non ultimate hard cc's / stuns. but you really, really want to have some. so much of this game is about cc and cc immunity. don't give your enemy a free on the whole cc game.