My initial thoughts:
1. I could do without the explicit Far Realm connection. The Far Realm is absent from Dark Sun lore, and not the primary source for psionic power in Eberron. These are the two published settings with the heaviest psionic influence, and the psionics rules should play well with those.
2. I like the basic structure: concentrate on a discipline to get a minor static bonus, spend PP to get bigger effects. Some of the specifics need work, however.
3. Mind Thrust: This is very wacky. IMO, it should force the target to make an Intelligence save or take damage, possibly doing half damage on a success (or perhaps have that as an potential upgrade, either via a straight-up class feature or via a discipline power). Also, I think it could do with a bit of automatic scaling, like a cantrip. Giving it a free 1d8 per tier sounds about right.
4. Psychic Mind: I don't have any problem with this, but someone earlier in the thread misunderstood it. The ability says the target can respond if you let it and it speaks at least one language. Someone thought that meant you needed a language in common, but that's not what it says. It's just there so you can't use it for two-way communication with creatures that lack language entirely, like most beasts.
5. Intellect Fortress: Could do with some abilities to spend points on.
6. Order of the Immortal: Since they're primarily "beat things up" characters, they could do with an extra attack. Though it's possible that that comes at 8th level instead of the customary 5th, because of the cleric parallels.
7. Psionic Regeneration: Should state that it does not work while unconscious.
8. Celerity - Surge of Action: I feel that this has too much potential for abuse, at the same time as the cost is very steep. Some have stated that they think this is an invitation to multi-class-dip into the Mystic class, but I think that's a small risk. After all, you need to be 5th level before using this ability, and I don't really think you can call a 5-level multi-class a "dip." But at the same time, it is kind of robbing the fighter of his biggest ability, and letting the character use it multiple times in quick succession, albeit at a steep cost (a 5th level mystic can do it 5 times). I think this would be better as a Cunning Action/Haste-like feature - something like "For one minute, you can take any of these actions as a bonus action: Attack (single attack only), Dash, Dodge, Help, Hide, or Use An Object."
9. Psionic Weapon - Lethal Strike: On the other hand (compared to issue 6), it's possible that this is supposed to be the Immortal's primary damage boost. If so, I don't approve on account of needing to have this discipline running in order to get it, and because it eats your psi points for what should be an at-will thing. It's also possible that this is supposed to be something on top of regular damage, in which case the reasonable thing to do would be to compare it to Divine Smite - at which point this is much superior. Smite gives +1d8 + 1d8 per spell slot expended, whereas this gives +3d10 for 3 PP which is the equivalent of a 2nd level slot, or +5d10 for 5 PP which is the equivalent of a 3rd level slot.
10. Psionic Weapon - Augmented Weapon: For a caster to get a +3 weapon out of the magic weapon spell, they have to use a 6th level slot. This guy gets it for 5 PP = 3rd level slot. OK, for a shorter duration (potentially - 1 minute vs 1 hour, but the 1 hour spell requires breakable concentration while this guy can't lose concentration to damage), but still.