Greythan, you can always look up just about anything on someone else on the WOW Armory website. That said, here's Luan: Luan's talents and glyphs

I think most of the discussion around /castsequence is not so much that it "gimps" DPS, but that your latency now plays a bigger part of how fast you cast. I'm usually hovering about 150ms latency, so I really don't mind the minor DPS drop. If you're something like 500ms latency on average, then you may want to invest the time in a /click method. I just didn't see any significant change when I tried.

Regarding Frost spec (and to some degree Fire too), I think you find that you have more proc management and "combos" to try to manage if you're going for maximum DPS. I just didn't want to make things more complicated than I needed when I assembled my team, though I have thought about trying some more complicated specs now that we have dualspecs. Arcane in general is very competitive for DPS and a rather simple rotation.