Thinking of returning, couple questions.
The personal stories still take place in Lion’s Arch.
Elementalists are very strong in PvE right now and one of the most desired professions for dungeons.
There is no map completion objectives on the new Edge of the Mists map.
To access Personal Story in Lion’s Arch, you would need to go to new NPCs outside what used to be the eastern entrance to the city in Gendarran Fields, who will smuggle you inside. The story instances are the same as they were before, except that they’re taking place in the burned out city.
World vs. World still counts towards world completion, yes. That said, there’s now a degree of randomness to matchups, so there’s more colour variance in the way the weekly teams are set up. As such, if all you’re missing is a few keeps, you should just need to wait for a matchup week where you’re the proper colour and you’ll be able to get them.
Can’t comment on elementalists, but whatever answers do come, there’s going to be another balance patch reasonably soon so it’s liable to change again.