As for the SLAs, well, you simply can't kill everything with slas. At best, after the nerf, you are forced to cycle in slas with other real spells. chain missle, ice storm, magic missle, chain missle, etc. arcane blast isn't worth it any way you slice it. Arcane bolt I found useful for the mere 25 max sp cost and only 1 ap.
Now, my build also had past life:wizard, so I was getting additional force slas, so moving out of evo focus when they nerfed it wasn't an option. If I didn't have past life: wizard, with a similar build I would be more likely to take sf/gsf necro, take no spell likes, and just max my sp (this is kind of what the dragonmarks let you do anyway). Its not necessarily a better build than going necromancer... but you don't have to worry about the weaknesses of being in form, anyone can heal you, you can heal others, AND you still end up with a lot of sp but higher necro dcs than a similar sorc.
Personally, I had pl:wiz, so I stayed evocation. The PL mms are always better than the sla mm, but you can run the build for forever. With a torc and a conc/opp item you can pretty much go for any length of time without pots or shrines. But the key at higher levels was to move away from dps against high hp mobs, and switch into necro. I took necro as my second chain, and circle of death and finger are still money while leveling with this build.
The build has its place, and its not on the bottom of the heap by any means. But you have to use your sp pool for a lot more than buffing and slas.
Hope that helps.