Can you go to other planets?

@AndrewGarrison Oh, that reminds me, is there a way you can make the gas giants not have a surface?

Yes and then half and half. The Gas Giants Tydos and Urados have a surface, but you can't land on them as your craft is automatically destroyed before you can land. Otherwise, you can land on Luna, Droo, and Cylero.

yep

Yes and yes.