Yes to the Static Charge question. Looks like a better spell now, doesn't it?

Multiple SC castings before a tough fight (or several tough fights, because the duration is so long) is a winning tactic - just be sure that whatever you're fighting takes damage from electricity.
If you feel like a little game-engine exploitation, a druid walking around invisible with multiple static charges can be fun... once. Don't do this on a regular basis, because it's cheap and gets boring really fast.
Produce Fire does not work the same way; it has to target an area, and only last for a couple of rounds, I believe. I know the description says one round, but it seems to last longer than that, such that any creatures in the AoE take damage twice.
Best results are on an area where you can rely on the critters to stay still - either in a "spelltrapped" area of Webs and Entangles, or right around your (fire-protected) lead tank.