Perhaps that is a solution for your 2. problem:

You create an event with three pages and call it elder.
On the first page you put that dialog. In the yes-case you change the switch "quest-1" to "on". At the second page you add this switch ("quest-1") to the start conditions. On that second page you make a dialog like "Search for that item.". On the third page you add the switch "item-x found" to the start conditions. On this page you can make your "Thank you"-dialog.

And in the dungeon you create the second event: the item.
This event just set the switch "item-x found" to "on" and add that item. You should add the switch "quest-1" to the strat conditions.

I hope that helps you. (And I hope you understand my English )

Manni