Glyph of Elemental Power and Signet of Fire both give the possibility of setting an enemy on fire a good fraction of of the time. Signet of Fire probably does that more efficiently, but that's all it does; GoEP has alternative benefits as well, namely your choice of Weakness or Cripple. Of course, it's easy to "over burn" as an elementalist -- and even more so for me, as I'll be duoing with another one.
Arcane Blast and
Frankly, all four of those seem like they're worth a skill point each to give one the option of equipping them.
That's about as far as I've gotten.
As for later on -- I've never taken Signet of Water in an sPvP build, but I suspect it might be good at the mid levels in PvE before I'm fully traited for condition removal.
Edited by FrancisCrawford, 23 July 2012 - 07:25 AM.