I can't transfer commodities out of my attached base into a ship. Rats, nukes, workers and pessies come to mind.
You can't modify commod prices directly in trade bay, (ie right click, "modify" doesn't work).
Also very difficult giving or taking credits from/to a trader. Almost seems to lock up the puter when you do so, (same screen as when you toss goods from a ship, it's a pain).