I think it's important to show I have some experience with more complicated effects and that a lot can be learned even if I wasn't as successful as I hoped.
I got stuck on my shader above but hope to get back to it one day to figure out how to fix the center... And yes the planets are just objects.
Yes colliders worked correctly on my generated land here. I got stuck figuring out how to curve my pieces into a circle and stitch them together though. Math was a bit beyond me at the time.
Procedural Noise Texture
A different style of creating procedural planets, yes yes lots of noise effects were used. This went on to other things and I had color setup and such.