I'm going to offer my input on this as someone who only played pure psi and only on DOMINATING difficulty:
Maximum amount of psi reserves is equal to 5 times the maximum psi points.
I can't see myself beating the hardest encounters on DOMINATING difficulty with just 6 bars of psi points. This only encourages zone transition cheese and AI abuse to drop combat and use inhalers.
multiple psi schools will now incur global 15% psi cost penalty per additional school
This makes the above even worse.
you're limited in the number of innervated psi slots (1 + 1 per 3 intelligence, up to maximum of 6)
That's 15 Int for just 6 spells? You can't use any weapon with all the points in Int, and 6 slots aren't enough to even use only the best stuff from just two schools. Not to mention that there won't be enough cooldowns to rotate, so you'll be stuck casting something like Neural Overload or Cryokinesis, which are worse than any weapon. And you'll fail to progress in the game.
What's going to happen is pure psionics will disappear. No other build will have access to more than 2-4 spells, so every psionic build will be one of the weapon builds, but with moderate investment in one school, or low investment in two.
Force Field is now destructable
Thermodynamic Destabilization base damage percentage changed to 30%
Enrage maximum duration changed to 2
Psycho-temporal contraction now has a high chance of causing its opposite (with randomized power) when it expires
Actually, I'm not sure if any veteran will even take the psi pill now. Just delete the magic from the game if you're gonna do all this, so that newbies don't screw up their builds by using it.
If you absolutely want to go through with these nerfs, change the spell slots to 1 per 2 Int, and add perks with high Will requirement that would at least double spell slot gains, double psi reserves, and maybe reduce multischool cost penalty. Though I'll just stick to an older version if I want to play a psionic, don't mind me.