The Quest notes are a little bit "I know how i meant it" but apart from that the quest is complete

That Fireplace is copied from Indiana Jones.

That last room is there to be avoided, for example. It contains three orcs equalling the loss of 1 BP if you work good together. Nothing else.

So, the entire thing was there to present Goldbearer something: Would the Questimator prediction come true?
The quest was designed to take 17 Body Points (give or take 4); plus 2 BP Wandering Monsters.
It actually took 14 (12 without wandering orcs). In between it was looking rather dark, but in the end you did everything right, every shot a hit, and you survived the final 6 BP room with the loss of a single BP! (well, and the elf

)
From statistics point of view, that last room was the only surprise in the quest. Well done!

Apart from that you were quite following the path of the statistic. My personal conclusion: This was the fifth test for the Questimator, and I stay convinced that it works.
I will continue to rate selfmade spells by how many BP they save for the Hero Group.
* Biggles for example added 2 BP to your group.
And I added the explosive mechancis as a 19 BP quest is rather deadly, and normally for more than one hero. You used the explosives once, saving one or two BP for your group. That's a kind of healing potion but one that is fun to use!

Plus, with it, you managed to avoid at least one room, saving you another BP more.