My suggestions:
Core Tech Tree: fine as it stands
Race/Civ Techs:
- Khuzdul: Longbeards: something with mining, agreed on needing mithril-working
- Khuzdul: Broadbeams & Firebeards: some mining thing, but enough to be equal to the Longbeards
- Quendi: Noldor: House of Feanor: something jewel-making, or maybe metalworking
- Quendi: Noldor: House of Fingolfin: something involving metalworking
- Quendi: Vanyar: some sort of tech either scientific or magic-y
- Quendi: Teleri: something involving improved ships
- Quendi: Sindarin: something involving forests - improved yields from forest tiles?
- Angband: corrupting the Elves sounds OK, though something else might present itself as equally relevant (possibly something with orc-spawning)
- Mordor: something to improve the usefulness of Hell-equivalent tiles (or whatever), though Angband could use that too
- Angmar: ?
- Isengard: something with industry definitely, uruks could also easily be a separate late-game tech
- Rohirrim: improved horsemen
- Dunlendings: ?
- Haradrim: either improved (or enabled) Mûmakil or improved desert yields
- Easterling: ?
- Numenor: something involving seafaring also, quite possibly identical or very similar to the Telerin one
- Gondor: construction sounds good
- Arnor: something with archery/rangers? something totally different?
- Northmen: ?
Alignment Techs:
- Evil: Slavery, maybe some other stuff involving improved relations/coordination with Angband/Mordor
- Neutral: --------------- (don't have anything, we want polarization)
- Good: Alliance against Morgoth? (i.e. something that lets good civs act like a team when it comes to fighting evil civs, or something to that effect)
Religious: - requires correct Alignment/Race/Civ
- Good: Light of Aman or something
- Dwarves: Teachings of Aulë or something, Light of Aman should also be possible
- Neutral: --------- (once again, shouldn't have anything)
- Evil Men: Worship of Morgoth
- Shadow: ? (seems like it should be different from the Men one somehow)