By design, you were suppose to have to chose which two people to save. However, you can get an extra cure potion by Pickpocketing one back from a cured person (level 2 required), by killing a cured person and having them drop the potion (with no drop in reputation) or by duplicating the potions before you start handing them out (see spoiler below).


You should just be able to tell Trevor that you got the black market dealer arrested. Some people have had problems clearing certain parts of this quest series.

Marcus-Tingalf-Trevor-Quest


You can cheat and duplicate the sword before putting it back in the stone, but by design you need to return it to seal in the ghost that would otherwise kill all the non-essential NPCs in the Dark Forest.

Sword from the Stone (56KB) - Fake Excalibur


Check out the screenshot maps in the link below for the location of the teleporter pad.

Silver Armour and Treasure Maps


To copy an item;
quick save the game, then drag an item out of your inventory, but not somewhere there is a red X. Without dropping first, quick load the game, then release the mouse button when it starts to load. This will produce a copy of the item on the ground, with the original still in your inventory.

There is a much easier method for items which can be stacked;
Drag a stack out of (or into) your inventory (or container) and hold down the control key before dropping. This will bring up the split stack pane; type in a negative number and hit enter (the checkmark will be greyed out). This can also be done in the trade window.