First of all, I apologize for my poor English.
A few suggestions regarding mostly pure psi builds:
1. Interdisciplinary abilities. Currently, every psionic discipline is in no way capable of influencing other psionic skills. Why not do some cross-skill abilities?
For example, the ability that allows using electrokinesis to turn the pyrokinesis fireball into ball lightning, causing electrical and energy damage. For balance reasons (and logical ones too), this ability shares a cooldown with Pyrokinesis, in fact, simply allowing you to attack with another type of damage.
Or, for example, the ability of Thoughts Control that allows you to use any temporal ability only on the thoughts of the enemy, but not on the body. That weakens abilities (for example, mental stasis is interrupted when attacking an enemy, etc.), but at the same time it allows you to impose them on the area using the Locus of Control.
2. Common Psionics
One of the main features of psionics in the game is the absence of 90% of baggage. Ammo - not needed, Grenades - not needed either (except for one achievement). Even TNT is not needed with the advent of Temporal Manipulation - rocks break through a combination of Implosion and Entropic Recurrence. Why not go further and create abilities that replace ordinary objects? In most cases, this will not affect the balance. Just a role-playing option.
Psionic Lighter (Metathermics 5) - replaces the lighter.
Psychokinetic Drill (Psychokinesis 50) replaces the jackhammer without the need to combine disciplines. According to Lore, a similar ability is possible - Bisson threw something similar, helping to clear up rubble after an earthquake.
Psionic Flare (Metathermics 30, Psychokinesis 30) - small amount of white-hot air, enclosed in a thin shell from a force field. Replaces flare.
Psychokinetic Lockpick (psychokinesis 60) gives you an eternal Lockpick, but without bonuses.
Psi-hacking (Thoughts Control 100, Psychokinesis 100) allows you to use your own brain as a Haxxor. Again, no bonuses.
Psilectric Recharge (Psychokinesis 70) - allows you to recharge things, replacing a huge number of batteries. I know, this is doubtful in terms of balance, at all.
