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To clarify your rotation it's better to see it as a priority list which is always as follow:
1) Flame Orb
2) Living Bomb
3) Pyroblast from proc
Use combustion with reasonable ignites (this depends on your toon and gear) and scorch while moving.
AOE is situational. The best aoe is spreading combustion so if you need to do aoe damage fast try to plan for this. After that it will depend on number of targets. In general what I do is if there are more than 5 targets I Flame blast then flamestrike spam. This will eat mana so you must also take that into consideration. If there are 4 or less targets I keep living bomb up on each and keep a regular rotation spreading all ignites with impact procs. My gear has me at about 32K single target dps and by spreading ignites I will do around 40K dps; spreading combustion can bring this number up to 70K for the duration and Blast wave/flamestrike on multiple targets is about 50K. (yoshr adds for example)
With your gear you should be doing closer to 30k dps so you're biggest problem is likely just not enough casting. To increase your dps ask yourself if there was any possible way you could've gotten more casts off in an encounter. Since we can cast while moving, this means that if you're not on GCD or casting at any time during the fight; there is room for improvement. We can have 100% active times; moving is no excuse for us to not be dpsing.