Who can help me with OVERLORD?

[GLH]

Perhaps someone can help me with this game.
I've some questions:

Normally all the quests in the list have a little Overlord-Sign, but the one, where you have to kill the giant snail and take back the goldwagon, has a little minion-sign. I already killed the giant snail and found a big treasure, but not a gold-wagon. The quest is not counted as quest (in the tower, when i activate the tower-heart), but when i go to the Arkanum Mine-Area, this quest is always listed.
Whats the solution for this?

In the desert, there is a giant sandworm. I already tried all four minion-classes, but can't kill that sandworm.
How can i beat him?

Also in the desert. There are some bone-barriers.
How can i destroy them?

[GLH]

OK. I found out how to kill that sandworm.
You have to let a minion take on of the firebeetle-eggs and bring it to the sandworm. A firebug will follow you. The sandworm will eat the minion+egg and the firebeetle explode. You need two eggs for one sandworm.

Also the bone-barriers can be destroyed this way.

[DABhand]

Only thing I remember from the Arcanium mines was the smelter and the top fire spell upgrade.