I go with all 4 schools, keeping TM at 70 though I also go with 12 int.
I'm not sure if this is troll or you play on easy, because 4 school is shit after the Psi Rework. Let alone innervation slot, you could barely cast stuff without exhausting your psi points, thus requiring unnecessary psi booster feats. Even 3 school is already pretty exhausting. 70 TM is barely viable because it still left you with huge chance of PTC backlash. If you still kept the mentality of adrenaline + PTC, you'll have a VERY bad time and enjoying 10 AP for 3 seconds after that...
I am not sure if I should take you seriously at all and I am not playing on easy difficulty, far from it in fact. PSI before the changes was one of the absolutely most destructive builds out there. Full PSI still works you just have more tedium with innvervating now but it is not like you deal less damage you just innervate according to the enemies given. PSI inhalants cost a little but not so much that you will be begging out in the Drop Zone of Core City for scraps.
70 TM with 15 will and PSI headbands+PSI beetle carapace does work well enough. APE, Hemopsychosis, mufflers and soup do suffice and you can one shot most groups with LoC+Mania+Trance+NO. Crit PSI does not need to care all that much about efficiency once you get to level 16+. You struggle more early game but much of that can be circumvented via stealth or right gameplay/skill choices.