You generally want to keep thunder for the ice phase if it eats an additional fire cast but not sure how that lines up at lower levels. Yeah that's about it, make sure to do your job quest to get Flare too for aoe, at the end of your mp bar, use flare then transpose > bliz III. Later you'll just be replacing Fire II with just Flares(once you get a trait that makes Flare not consume your entire mp bar if you have a frost buff you get at that lvl too). The rotation will change once you hit 60 however, once you get Fire IV it's when shit gets serious(also big booms everywhere instead of puny fireballs).
You're about to enter the shitfest that's post ARR MSQ however, so might want to get some shit to watch on the sides while you grind through 2.1 to 2.4 stuff. After that it gets ok and then Heavensward starts and a lot of that shit is more streamlined, less filler quests, less fetch shit, more story, more cutscenes.