So I presently have a level 8 Tiefling fire sorc now who should get to level 10 fairly shortly. I have 13 racial AP bonus (all but tiefling plus a +2 tome).

Some experiences: I wanted to like the darkness thing, but it's really annoying to use. Maybe that'll change once I have quicken. So watch this space.

Ash: Ash is really good with improved scorch---which btw appears to affect all your scorches, not just your SLA scorches. What this gives you is the ability to disable fire immunity more or less at will. Scorch is an AE. With castable and SLA scorch you're in business. Downside: it shares a cooldown with your SLA scorch from fire savant.
What I think will work though is just putting 1 point in racial scorch so as to get improved scorch, and putting the 3 into the racial SLA.

Improved scorch is a strong buy though. I think it's an enhancement justifying a build.
the Incinerate enhancements are also strong buys. +4% spell crit and +4 more for fire, sign me up.

I'm going to also try to make Infernal sovereign (electric) work. Why electric? I figure that since I'm going to be wearing the burnscar sash more or less all the time from 10-20, my acid spell power is going to be really good anyway. And electric has some good spells to round out my offense.

I'm seriously considering only taking one savant. If I take electric savant, it nerfs earth, which hits meteor swarm if I recall. And I get to inherit my fire spell power on electric anyway. So the question is, what to spend those AP on?

I'm contemplating actually burning a bunch in EK. For 11 points, you get a pretty serviceable spellblade and 20 universal spell power. for 21 points, you get a better spellblade (d8s) and 30 USP. For 31, (d10s) and 40 USP. 40 USP is pretty respectable. But how to spend 31 points for good value in EK for a sorc?

41 fire 31 ek and last 8 in racial might be a pretty good build. Lots of spell power, a great secondary through infernal sovereign, and a good backup in acid. And the melee option for finishing off the weakened might be decent. I think the tiefling d4 d6 and d8 at 75 50 and 25 all stack.

Any thoughts?