if you don't like the 5 choices you have, just enter your ship and they change....don't like those? exit the ship and they change again. at least that's what i do, and i only run Rich missions most of the time
But there are two things you are missing out on. Before you step in your ship and randomize your list again, should you choose missions out of the undesirable ones that are available, and does it matter which missions you choose? The answer is yes to both.