[Un] .. at a loss ..

[Arralen]

Hello folks, I'm trying out Un for some time now, but it's the first time I got as deep as BD15 .. and I'm really at a loss what to do now :

Level feeling & vaults
The level is "superb". I only found a magical shovel and some ?oMapping .. monsters where only some dragonflies and icky things. So where is the superbness? I vaguely remember reading something about hidden vaults, not connected to the rest of the level and not scryable by any means - how am I supposed to find them? Can't dig granite wall with that shovel, and my WandOfMud has only 10 charges or so ...

Runes
I found some runes. I know I'm supposed to "y"apply them, eg. to my weapon, but what is that good for (blood rune stone, eye rune stone)? And how can I find that out? Or are those things -and any *ID*- that much "work in progress" that they either do not work at all atm., or it changes from subversion to subversion ?

Bags
I found a "Magical Bag of Supplies". How is it supposed to work? Looks like I can store spikes, oil flasks and empty bottles in it, but no food items. Strange .. would have though "supplies" are food, and maybe something else .. so what is supposed to go into the different bags?