Has anyone made bigger planets?

[Suicide Junkie]

Making things lots larger causes problems. Roundoff error in the rendering and stuff makes it look sub-optimal.
You also have to go through every system and increase the shuttle-over distance.

Instead, I reccommend scaling down the ships and bases.
Change the model scalings, and divide the top speed of each hull. Divide the camera distance.
Then divide the thrust produced by each engine.

From your point of view, the ship will be the same size, but the map and planets and stuff will be much much bigger.