Duplicate items
Press [Alt] + S to quick save the game while in your sector. Take an item from the speed inventory bar at the bottom of the screen and keep it "floating". Press [Alt] + R to restore the game. The selected item should still be in-hand as well as in the inventory. Place the "floating" item into an open location in the inventory to obtain two of the same item.
No action point limit
Direct one of the mercs to travel a longer distance than the available action points. Watch the action point total as it decreases. When the action points are below the number needed to shoot, but still more than zero, click the Right Mouse Button on the merc to spin it around and display three buttons. Click on the "Reserve Points" button, which should have been unchecked previously. Click the Right Mouse Button on the merc to spin it back. The merc will continue walking to the destination while ignoring the action point limit.
Not so busy after all
When using a mercenary that refuses to take different orders after they've engaged an enemy (such as Fidel and Leech), simply remove their weapon from their hand (taking them out of combat mode) and put it right back. Since you have not moved the weapon around in their inventory, this costs no action points, but they will be willing to take orders again.
Duplicate items...