Help me to choose my profession
Staff Elementalist is often regarded as a support set, but it can actually do a lot of DPS. With certain builds, Staff can have the highest Ele damage output without relying on conditions.
Elementalist’s damage output is also increased if you Elite Spec them to become a Tempest. Tempest’s Overload skills can do a lot of AoE damage, particularly the Overload Air.
You’re also open to doing support if you want. You can maintain optimal Tempest damage while using “Elemental Bastion” which basically does a big chunk of healing every time you activate an Aura and you can always just use Water Attunement when ever you feel the need to be a bit supportive.
Staff skins are quite good as well. Lots of variety, since you sound like the type of person who’s into the cosmetic side of the game.
Other than Elementalist, I think Mesmer Elite Specialized as a Chronomancer could work. Mesmer was regarded by ArenaNet as the hardest and most complex profession to play at launch. Without Chronomancer, Mesmer is very single-target damage based, but Chronomancer grants it access to Well skills, which are basically giant circular areas that pulse out damage and other effects.
Elementalist (Tempest with Staff)
or Mesmer (Chronomancer)
Take a look into those two things and see what you like. Getting Elite Specializations is difficult, but you can test them for free in The Heart of The Mists on the training golems there. (Go to your PvP tab to access it.)