SCH is always the best choice for dps.

But let me see, if you want something reactive how about a proc based class, BRD or maybe MCH? MCH does take planning out cool down usage though but then most if not all dos I can think of will have that to varying degrees. MNK's basic rotation seems simple enough to not be too distracting that you'll be reacting to mechanics and spinning top tanks

I don't really play a lot of dps classes and really only one at 60. I hated SMN for the reasons you mention. I enjoy MCH more but it's not for everyone. I am going to try MNK next as so far it seems less tedious but a lvl 60 should comment on that.