So a guy really pressured you on DPS in a 40 dungeon ? Where as you say it's around 100 DPS ? Man, what a time to be alive...

Seriously don't listen.

Only worry about your rotation when you're 50 : get a simple guide and listen to Kabooa's advice. From there on, you only add skills in the rotations.
Finally, when you're 70, you can really look into guides that are on this forum. If you want you can read them right away, but don't let yourself be given crap on DPS in anything that isn't 70