My thoughts on equipment to keep: First, we should keep two complete outfits of low level gear, for starting new characters, but no more. To my mind, this would be full Sigon’s (x2), a Civerb’s Cudgel and/or an Isenhart’s Lightbrand (x2), a decent normal unique bow (only one), full Infernal Tools set (only one), an orb with +3 charged bolt (only one), and two Cathan’s rings and amulet (x2). That way, even if two folks start new characters at the same time, we can equip them both, and with that selection of items, any character class can find something they’re comfortable with for the first 20 or 30 levels. I would dump all other low-level items, since I don’t think that there’s any real use for any of the other low sets or uniques. If you have a specific build in mind which would use any other low set items, say so, and we’ll save one each of those specific items.
For low uniques, the only normal uniques which I think are worth saving are Magefist and Frostburns for casters, Goldwrap, Tarnhelm, and Chance Guards for MF, Iceblink for the freezing, and Silks of the Victor. In addition, we should keep one (and only one) Venom Ward and Boneflesh, for mercs, Culwen’s Point, for an A3 non-fire merc, Goblin Toe, for CB, and Wormskull, for necros. No normal unique weapon is better than Civerb’s/Isenhart’s, IMO, so don’t bother saving any of them.
On rares, a lot of the things we saved were decent at the beginning of the ladder season when we were poor, but no more. If, for a rare you see, you know that we already have something else that’s better, toss it without consultation. This would include all of the +1 to a tree helms that Who_me? mentioned, since we now have +1 to all skills helms in abundance (unless, of course, it’s got other attributes worth saving). This also means helms/amulets with +2 to a skill tree, if we also have one that’s +3 to that tree or +2 to that class’s skills. Things with +2 to a class or +3 to a tree, we should probably save for now, I’d say.
Also, I propose that the next account of mules should be one of each character class, for items suited to a particular class. This would mean that class’s class-only items, items in the class’s set, and items which give a bonus to that class’s skills. The eighth slot could be mercenary items, for our polearm collection and leech armor/helms.
On a completely different note: Hirka, I would recommend that you enter Hell when and only when you think you can reliably handle lightning-immune monsters. In my experience, monster immunities are the biggest difference between Nightmare and Hell. As a melee character, you’ll also want a fair number of hitpoints (I’d say probably 700 at a minimum, preferably over 1000), high resists (Lightning 85, others 50 or more, and remember the Hell penalty) and maxed blocking (you do have Holy Shield, right?), since Hell monsters hit harder than NM. Tesladins have pretty high damage, though, so you probably won’t have much trouble killing non-immunes.