For the ethics- to a certain extent, what's considered cheating by some is only considered cheese by others (such as atma, which i do use, btw). The item etc., packs that were posted here were 'legit' in sofar as being posted by the site admin. however, i think most of us consider them cheese.
anywho, for a merc- i will say that my only experience thus far with a caster+merc has been a sorc. I started out with a def. merc, and he rarely died. I now have a lv 79 HF merc, and he dies, a lot, to an annoying degree actually, I mean, really, a lot, such that I leave him dead often. Did i mention he dies a lot (this is in hell, btw). I'm guessing he's highly dependant on leaching, and I'm going to have to start playing with equipment, weapons with amn runes, etc, to get his ll up (and I don't have anything godly for him atm either). There are some tactics i'm considering, but they won't work with a caster pally, unless you have teleport charges (slow packs with HF, then jump backwards to keep the merc from being swarmed). Anywho, i liked the defiance merc better, but we'll see how things go with the HF merc after some serious equipment searching. So...Still a tough call- the defiant tanked better, but it is nice to chill and slow things.
The real question is 'what is your style of play????' This will make all the difference as to whether you want a HF or a Def merc to tank for you. Consider if you like things slowed so you can move back, do you have trouble with archer packs (fewer shots vs higher def- any of you number crunchers out there have an educated opinion?), do you like the excitement of being in a pack of monsters and demons while you spam hammers and possibly zeal for crowd control (that'll be me if i ever have a hammerdin)...so, which fits you better? :spy: There are some who don't use mercs at all even, so again, it's really dependant on how you play.
heh, you could buck the system entirely and get and act 1 merc :teeth:. I've got one as back up for a zealot (in actIV hell, no less), and it's fun.

I'd recommend fire over cold, but that's just because they level faster, and you can socket cold dmg to a bow.
just my 2 ccs,
WJ