Start on any of the first three planets: Vulcanus, Gleba, or Fulgora.
Choose your planet in the startup mod settings before starting a new game.
Compatible with many modded planets!
Not easily, no. It doesn't work for a variety of reasons, mainly technology progression being all sorts of messed up, however you can try Planet Picker instead which lets you choose the planet you start on when you join. Pretty sure the way it works is by unlocking everything you need to start on the other planets right from the start, so the progression is a little messed up, but it does let you start on different planets.
