1. They can go quite a while between results, just be patient. If there's nothing more to find it will give you a warning about it in the events window.
2. You can make civilian shipping orders from the "Civilians / Ind Status" tab in the economics window. As far as I know, the orders have to be matching pairs (so you would have to make 2 supply orders of 50 mines to fill 2 demand orders of 50, rather than 1 supply order of 100 to fill them both). Civvies can only ship installations as far as I'm aware, but their colony ships will automatically pick up colonists and drop them off on your colony worlds. Any mineral/component movement you have to use your own freighters for.