I watched a video yesterday that explained why roaming a planet is pointless due to how the game is designed. Basically, every time you pop down to a spot on a planet (not a static designed city), the game randomly generates the terrain. Each and every time. So if you roam area A, pop up to orbit, pop down to area B that's adjacent to area A, then you're not going to find the Same terrain that you found the previous time you were at area A. So aside from popping down for resources, there's no reason to spend all that much time on a planet it seems. The upside is that you probably won't deplete that planet of resources (from the little I've played).
Oh and it's REAL EASY to fill up all your starting storage, but so long as you don't go mining right away, then you'll be able to grab all the loot from the first story area (from start of game to the first settlement) all while being only 200% over encumbered. π TBH, you'll want to do it as you'll double the measly amount of credits you find / start with to that point. That's as far as I've played though, so IDK how maximizing credits is going to go yet, but I do see just how expensive things like ships are going to be. O.O