I think you overvalue Chaos heavily, undervalue Antimagic, and undervalue Venom early, plus not treating Flaming/Freezing as the same, or having Flaming slightly higher because of hydras is odd.
The list is based on how happy I am to see each brand, and I actually am really happy to see Chaos, I just absolutely
never use it. It can clone enemies, however, so Best Brand Ever TM
Antimagic is pretty decent in Zot, as it works on Orbs of Fire and liches, and is (IMO) the second best brand for extended, but early game weapons seem to do too little damage to successfully lock down a caster, unless you're going Trog/Oka to get better chance at high-damage weapon gifts.
Freezing I find a lot better than Flaming, as it slows down cold-blooded enemies (useful in Lair, Snake and oddly enough Zot, as it works on Draconians), also I think less demons resist Cold than Fire, but for the life of me I can't find a list. Flaming is good against Hydras, but so are wands, evocables, god powers, all non-bladed weapons and ranged.
Reallistically for extended you would want either Holy or Antimagic, unless you're a caster wielding something for the resists. Vorpal is better than nothing, but almost everything is better than nothing (ahem Distortion ahem). Speed would work in the very niche case where you find an Executioner axe of Speed or some such, and can stop training the weapon skill a lot earlier to focus on other areas, but that has happened like, once, to me. Venom is amazing pre-lair and that's it. Electrocution is a reliable brand all the way to Zot, but Holy and Antimagic swiftly overpower it. I hear Pain is good with necromancy pre-extended, too.
This is all my personal experience, as I haven't really sat down to crunch the numbers with facts, so if anyone has data I'd love to see it and adjust my play accordingly.