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.

Skip opponent's turn
Press [Ctrl] + F When it is your opponents turn to move to skip back to your turn.

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.