Note! This is just a preview; I have not yet uploaded a new version of the mod.
Ok... thanks for all your input! These are the changes I've made so far (many from forum input, many not). At least, the ones I've documented. I still need to look at some other things (like archer costs, adjusting longbows, and messing with BF Ulm's mages). If you have any problems with the changes, please say so...
Cosmetic Changes:
Added a bunch of new weapons and armors (maybe 10 of each) These are generally for aesthetics (like gilded armors, silver armors, etc) and do not change balance. Even the ones with different stats often don't change anything, but I'll list some:
Avalon Knights get silver armor - just like regular full chain, but -1 encumbrance. This has no effect since they are mounted.
Ulm units with full helms get Full Hlmet of Ulm. This is 2 prot, 0 def, 0 enc. In other words, a weaker version of the Black Steel Helmet. Since this has no effect other than giving units +1 defense, and defense is virtually useless to Ulm units, it probably has no measurable effect.
Fire Lord and all Marignon's gold-colored units get Gilded Armor. Stats do not change.
Tien Chi Eunichs get kung-fu training, and learn Punch and Kick (instead of Fist). They are now able to beat blood slaves in combat, which you sort of expect from a field commander.
Tien Chi healing immortal gets a magical pruning knife.
All TC immortals get super weak armor (Immortal's Robes (2, 0, 0), or Flea-Infested Cape (1, 0, 0) for the old man).
Important Changes:
Tien Chi immortal swordsman got way better. He was terrible before (in combat) partly because he had 2 weapons and no ambidextrity. However, some of the bonus is integrated into his sword and "imaginary" shield, so giving him a new weapon and shield will make them go away again (somewhat).
Sling becomes -1 prec instead of... whatever it was (-3?).
Slingers get 9 prec (-1, total of 8 with sling). They're still terrible, except against flagellants or with flaming missiles, but better than before.
Man Foresters got better stats and supplybonus 2 (feed themselves and 1 other person, probably with rabbits and truffles).
Throwing axe precision went from -4 to -2.
Axe Thrower gets precision 9.
Lobo Guard dropped -1 hp, -1 att, -1 def, since they were abused to the point of mindlessness.
Hoburgs got lower resource costs. Just as big units have higher rcost for armor, tiny units deserve lower rcosts for armor. I doubt anyone built Hoburg HI, especially since (I think) hoburgs are grassland-only.
Crab Hybrid gets ambidextrous 4 (since I gave pincers length 2 rather than default 0)
Spider Warrior dagger replaced by Poison Dagger. Makes sense, right?
Man's Green Knight gets custom armor, reinvigoration 1, and regen 15% (instead of 10%).
Machaka riderless spiders get upkeep (great spider: gcost 10 {.66g/turn}, hunter spider: gcost 30 + sacred {1g/turn}). They are still an incredibly good deal, but someone needs to be paid to tend them (they don't get the money).
MAR Royal Xbows became 10g (+1).
Knights of the Chalice went back to 90g (+10)
Daoine Sidhe back to 35g (+3)
Ulm Rangers: I wanted to give them a patrol bonus but there is no way to do that yet

Instead they got #neednoteat (and a description change about wilderness survival) and traded axe (terrible weapon) for shortsword (good weapon). Gold cost: +1 to 13g. They should still avoid melee, but at least have a chance.
Ranger Captain: +5g (to 50g) and leadership went from 10 to 25. Also, same changes as Ranger.
Black Forest Ulm Commander: 25 leadership went to 50 leadership, to be on par with other Commanders of Ulm. BF units are weaker, anyway.
Black Knight: Returned to 60 gold (+10)
Non-unit changes:
Added #foodmult 150. This gives 50% more supplies. It makes the AI less likely to starve, makes units that eat less disadvantageous over non-eating summons, makes light units and militias more useful, and reduces the need for winebags, summer swords, cauldrons of broth, and nature picks on pretenders specifically for those items. If / when I make Chuckwagon units, this might be taken back out. The constant need for magical winebags when using mundane troops is annoying.
IMO, a higher #foodmult over default is vital to balance units... though I admit it is not an ideal solution, and it won't magically make hordes of militia as desirable and useful as hordes of vinemen or longdead.
Sound ok? Aside from things still to do, of course.
For example... I'm considering increasing the price of every recruitable mage in the game by 10%, EXCEPT the ones that are already "too expensive". If a 180 gold mage (say, a Vanheim Dwarf) can kill 50 units unboosted in a couple battles in the early game... why is he much cheaper than those 50 units? It makes you want to spend all your money on mages (which is what good players often do). 10% probably is not enough, but I'll do it and see how it feels.