edit files?

[tummychow]

I was fiddling with the edit files to add some new artifacts (they were cheap and unfair. I play Angband for the fun of it, not to boast that I won!) and such, and I wanted some clarification on some of the edit functions.
ONE: How do you add ring or amulet artifacts? I found some related bits in the objects edit file but I'm not sure I understand fully. And is there *any* way to exceed the 15-piece limit on those special artifacts?
TWO: How do I examine the contents of spellbooks and add new spells, or edit the effect of existing spells? The spellbook edit file only lets me edit the mana costs and fail rates of the spells already present.
THREE: Can I every modify the shops to increase the slots in them? In particular, can I expand my house to hold more items?