So I decided to play pure psi on my very first playthrough, on hard, with no reading of stuff beforehand.
Str: 4
Dex: 4
Agi: 4
Con: 4
Per: 8
Will: 8
Int: 8
Skills:
All 3 psi
Hacking/lockpicking
Crafting (mostly electronics, tailoring, and mechanics)
Persuasion
Initially I was gonna go dodge/evasion route, but there's one major problem with that route in general: You can craft tactical vests with a psi beetle carapace that improve your psi skills and reduce psi costs but has a pretty hefty armor penalty. Enough that Nimble no longer takes you down to 0 penalty so you're still taking hits to dodge/evasion. I have Nimble too, and the reduced armor penalty is still good, but it's not enough to make Dodge/Evasion my primary defenses.
What I would do if I was gonna start over:
Str: 4
Dex: 3
Agi: 3
Con: 7
Per: 7
Will: 8
Int: 8
I've had reasonable success with my current build (I was powerful enough to kill Eidein at level 20 if I wanted to), and I think it'd be better with those stat changes. Your first two stat pumps go to Will, then probably Con, or maybe a point or two of Int if it gives you an extra psi per round. My Con is still too low (I've pumped it to 6 but still low) and many times if my opponents get a chance to attack me without my defenses up I just die. But I don't think 10 con is entirely necessary, it seems needlessly min-maxed (Remember that I'm playing on Hard. I know how tough the game can be in parts).
In combat, you have a huge array of debilitating and defensive abilities at your disposal. Use them. Telekinetic Barrier to pause a battle is your friend. Especially if you can fit an Enrage in there first once you get that. The Force User feat and a Telekinetic Proxy/Punch can throw out a lot of single-target damage.
Ehh, just a few thoughts.