I'm in the process of renovating my new home and will move soon. I'll edit my guides to comply with revised forum rules at a later date. I've been so busy that I just noticed the revision.
if you plan on changing any content, i'll suggest a correction, and a note on gambling:
there was no such thing as magic level until 1.07. the +2 that amulets get is actually
global, it applies to absolutely everything. (every item, every source.)
so if a monster with mlvl6 drops an item, then the "qlvl"=6+2. if a player of clvl38 shops staves at nightmare, qlvl=38+2. etc.
similarly, imbue ilvl=clvl+4, and then gets the +2 bonus. gamble ilvl=-5 +4, then +2. (again, not just amulets, everything gets this bonus.)
and a small note on gambling, i'm not sure if it's know, but: ilvl=clvl-RND(10)+4
what difference does it make? well, after the subtraction, if ilvl is <1, then ilvl=1. and
then the +4.
so at the very minimum, ilvl=5, and therefore the minimum qlvl is 7. (so even at clvl1, qlvl is guaranteed to be high enough to spawn affixes of lvl 7.)
i realize my noname-self doesn't have a great amount of credibility, so if anyone could chime in to confirm?

this forum is too good to house misinformation. right? B)
especially the global +2 i mentioned is easily confirmed. ilvl = clvl when you shop vendor items, so with an affix table handy, check out charsi her inventory. you'll find that her items can have affixes 2 levels above your clvl. (but keep in mind the ilvl caps on normal.)
the second one also isn't hard to test, but certainly more tedious: take a clvl 1 char and gamble some stuff, you would see that affixes up to alvl 7 can spawn at that clvl.
@Barl
vengeance might be fun

i wouldn't touch zeal on hardcore myself. (perhaps with absurdly high AR.)
and in case you were still interested in bone farming, last week i did a bit more testing and know now exactly what walls can drop.
on nightmare and hell they use the same treasureclass, but because mlvl is 32 in nightmare and 57 in hell, there are a bunch of items that won't drop on nightmare. (which means they are more likely not to drop anything.) furthermore, a lot of affixes won't be able to spawn on nightmare.
i won't discuss Normal bone walls too much, since they're only mlvl 7: the game
first picks a base item, and
then compares the lvl of that base with mlvl+3, so the walls will drop nothing most of the time because 10 is often too low for the picked base. (and of course the affix pool is terrible as well.)
some factz and assumptionz:
- MF
sometimes applies. unfortunately i don't know why it sometimes does (not). note that MF will only apply if you kill(destroy) the walls.
- walls can drop any quality, including rares and uniques.
- health of the segments scales with player number just like the health of normal monsters does. walls also have "standard" health regeneration (2).
- high poison and high cold resistance. 0 resistance to all other damage types.
- each segment has its own life, and its own regeneration. segments don't share damage. if one segment drops, they all drop, so AoE won't do you any good: focus fire on one segment. (or just let the timer expire, but then MF surely won't apply.)
- i'm
pretty sure that 1 wall can only drop 1 item, regardless of how many segments the wall has.
- i'm
pretty sure that the number of players in the game has an effect on the "nodrop" chance. and if that's true, it would be most efficient to farm at P5.
in single-player testing, it seemed that walls go "inactive" after about 4 seconds:
i would spawn walls in the cow level, take the red portal back to town, wait 5 seconds, and that would consistently do it. in multi-player it was less reliable, unfortunately.
anyway, it's not pretty, but here are two lists. at the top are the affixes that
can not spawn on Hell due to the mlvl being too low. everything else can spawn.
below it are all the items that the walls can spawn on Hell. imo i would not bother farming on nightmare or normal.
and if you were wondering why the +2 skills affix isn't shown, well as you can see below, amulets can't drop at all, so those affixes are irrelevant.
also note that most items, even though they can't spawn a certain listed affix,
can spawn higher versions of it. (for example a belt can't spawn 31-39 life, but it can spawn 41-59 life.)
Hell Bone Wall drops:
edit: WHOOPS, sorry for the wall. :-( it didn't seem like that much as i was typing it.