Only places you can't dock large ships are outposts which only have medium or small pads.
Yes. Also in the mission description you will see "(Outpost)" next to the station name if it's an outpost (where you can not land) so it should be clear even if it's offered to you.
its not a bug the people at the station simply have jobs for you but its your problem if the ship isnt compatible
If you wanted to smuggle something into a system, would you give the job to the pilot of a small, fast, unobtrusive ship, or a dirty great huge, loud beast of a ship?
Hmmm, let me think?
Also, it's good practice to check on the system map before accepting a mission, to ensure you can land there!