Help on a few triggers

I'm kind of stumped on 3 triggers:

1. I want a trigger where, when a player creates a building in a certain region, the building detonates, the region and surrounding regions where the building is built will kill all units in them.

2. I need to know how to make a random item drop when you destroy any building.

3. Last, I need to know how to make trigger where lets say u build a farm for 1 gold, and when the farm is destroyed, it gives u 1 gold back.

I'm sorry if I'm a burden for asking these questions. I don't have much time to spend on making maps.

1.

Event -> Unit Owned by Player(X) Finishes Construction

Condition -> (EventResponse(Constructed_Structure)==Whatever)

Action ->
Unit Group - Pick Every Unit in Region(X) and do (Unit - Kill (Picked Unit))
Unit - Explode EventReponse(Constructed_Structure)

2.

Event -> Unit Owned by Player(X) Dies

Condtion -> Dying Unit is a (Structure)

Action ->
Item-Create (Random Item type of Level (X) at UnitPosition(Position of Dying Unit)

3.

Event -> Unit Owned by Player(X) Dies

Condition -> Dying Unit Type is Farm

Action ->
Player Property (Add 1 gold to Player(X) Property Gold)