The reality is that, right now, high-end content is something people go to Aether for due to everyone using DC travel. In every region, it's caused one DC to be the "raid DC".
But that doesn't mean you have to make your character on Aether. You can use DC travel to go to Aether when you actually want to raid.
Dynamis is a new data center with a lot of capacity and it needs its population to grow. But that sometimes means you need travel to other NA data centers to get things done until its population grows enough.
Any other NA data center is fine. On any other one, you can queue for duties and you are fine. Again, it's easy to travel to Aether if you need to. Aether gets congested a lot, so it is considerate to not contribute to that problem by making a character there. Primal and Crystal are great when you're not raiding.
You mentioned Jenova. It would be a good idea to go to Jenova rather than Gilgamesh because Gilgamesh is more congested. It's congested because of how it is regarded as a raiding world. But you don't really need to be on that world to raid or to join a static. Even people from Dynamis join Aether statics now thanks to DC travel.
Jenova is "good community and good vibes" for sure. Gilgamesh can be more mixed being such a large server.
