More Variety in Worlds

To make most of these ideas work, I would need the world size to be bigger, otherwise everything would either be small or cramped. Maybe even have a new world size? Small, Medium, Large & Extreme?

Outer Space
  Outer Space isn't very... I don't know, expansive in Terraria? Maybe the world height could be raised so we can actually have an outer space biome with UFO's and aliens as enemies. Maybe even floating bits of rock like small meteoroids orbiting the planet? Just an idea :)

Volcanoes & Mountains
  Maybe we could have real mountains in Terraria that even may be able to be volcanoes? They can be topped with snow and be really tall. The volcanoes however, won't have snow on them and instead have a crater that goes through the mountain and down to the point where lava starts appearing underground with a massive lava pool. These volcanoes could even have their lava slowly raise and if they get high enough, erupt?