Personally the way I find it to work better is this (again this is how it works better for me, doesn't means it will for otehrs, eachone has it's playstyle).
Str-3
Per-7
Will-10
All else-5
Weapons I take crossbows only. Ammo is cheap and you got special ammo to do lots of stuff but the only ones I really find useful are the shockbolts which are agood against robots and more importantly, stun.
I take stealth for inniciating combat on your terms!
Hacking and lockpicking for loot obviously!
I take the 3 psionic skills
I get persuasion because intimidating only helps defusing situations and persuasion usually also helps but to be hones any situation that you can't defuse by persuasion is better just to kill everything and get the loot anyway. Mercantile is cool, but ultimatly doesn't helps to swing people in your favor and get you extra side quests.
For feats I take aimed shot and snooping. Aimed shot you don't really need an explanaition and snooping gets your perception to 10 so I'll spot all hidden stuff.
As I level up I don't need to dip into other stuff, only raise all of those skills. For abillity only raise will because that gives more damage to my psionics and gives me more psi points to use. For feats, I get this in this specific order. Shroomhead to regenerate my psi-points for free, just goijg back and forth to mushrooms as necessary until I have enough money to spam as many psi-boosters as I care to. Force user to give my stun punch more damage and my abillity to block passages for one extra round which is incredibly useful. Locus of control, you aren't going to be stunned anymore not to mention casting thought control abillities as an huge AoE. Premeditation next for extra range and less energy spenditure on the next spell. Marksman next since i can use my bolts to stun, I better not spend more than 25 action points in it as it will further limit my psi-abillities option for that round. Doctor next to be able to always use the bandages which is very useful. Last I get cerebral trauma. You probably won't get any more as at this point you're at the end of the alpha.
Now what do I do with this?
Well let me tell you all the moves I can pull with this. You got 2 stun spells and you can throw them on the same turn. You have fear to make enemies flee and if you want to get a lot of them running, you can use locus of control to mass cast it. You can 3 turn stun someone with mental breakdown and you can mass cast it too with locus of control. bilocation is situational but can be incredibly useful, especially against mutants. Cast it, use the force field so that no one can get to you anymore and you'll have 3 rounds of your dopplegangers killing on guy. Imagine there are multiple human or humanoid targets. You can use locus of control to mass cast the dopplegangers which will create one for each enemy and facter that force field to barricate yourself... the amount of control you have over your enemies with a stealthed psiker is just bonkers and I love it
