For the levers, you need to get all of the doors to the 4 small rooms open, then pull the central lever to close those doors and open the treasure room.
Specifically, exit the house via the teleporter pad to reset the levers, then enter and pull the north west lever, then the south east lever, and finally the central lever. The north east and south west levers remain in the up position.
Down (1) ..... Up
... Down (3) ...
Up ..... Down (2)
With the loan, simply pay it back. At least later in the game it is easy to get money. If you do not want to pay any interest for an accidental speech option selection, there is a way to cheat to get the required gold.
To duplicate items that 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.