I'm sure the answer to this is probably 'No', but are you allowed to land bigger spacecraft like motherships directly on a planet like you can with a Sleipnir or Quad-Wing or can they only be moored at a planet's space station?
Motherships and privateers can be docked at a space station. Currently they cannot land onto a planet.
What George said. Closest you can do is with the Motherships which have a Hanger and Portal on them is that they will back up to the Planet Server Boarder and when you fly out of the ship you are asked if you want to Dock on the Planet. You don't even load Space on your screen, you go directly from inside the ship to the planet.
Thanks, just as I thought. Still, as I remember it, owners of the old hangers before the typhon impact were supposed to be compensated with a new hanger, but what use would they be if you can't use them for larger space craft...