Can you change the size of meshes just by editing the .Meshes files in Notepad? I was hoping to do a little bit of scaling for some of my planets (only 30% bigger or so, nothing drastic), but my skills on modeling are non-existent at this time.

No, you can't change it that way; you can edit the bounding radius value, but it has no effect (other than collision detection I believe) since each vertice has its own spatial coordinate value relative to the object center. So you would actually have to edit every single vertex coords, which is impossible to do by hand even if you had the patience for it.

The way I did it was, I created a brand new mesh (I love modelling planets, just slap a sphere on ), UV mapped it, and then simply converted it to the desired filenames (planet_terran_0.mesh, planet_terran_1.mesh etc.). The good thing is, other stuff like planet elevators adapt automatically, so I ended up with a really nice and believable planetary traffic without having to tweak anything. There are some issues with planetary glow, but that should be fixed easily I believe. I'll post some screens in the Last Stand thread when I touch them up.

Also to note, if you change planet sizes, you also need to change the max camera zoom in value found in planet .entity files, otherwise you can zoom in straight inside the planet.