There's something missing from combat in FFXIV. As things are, interaction between players during combat is just like every other "holy trinity (tank/healer/dd)" MMO out there. Tanks worry about positioning and mitigation, DD worry about dealing damage without pulling hate, and healers worry about healing tanks and DD that take hits. All while everyone tries to stay out of puddles. You can find these kinds of challenges in tons of other games.

Meanwhile, the Skill Chain & Magic Burst (SC/MB) system from FFXI was a FF unique combat mechanic that gave great rewards to groups capable of time-sensitive coordination. I recognize that 1) FFXIV shouldn't be an FFXI clone and 2) FFXIV combat is a bit fast for the SC/MB system of yore, but I think there's room to mingle the SC/MB concept with Limit Breaks.