a) wisdom
Each rank in it grants additional 2% to your experience gains (doesn´t work retroactively).
Investing into this early may eventually grant you few more levels, but the investments also mean you have to cut the points from other skills.
It almost seems like devs put it in there as a trap for people who didn´t do the math, because it really isn´t worth it, iirc I came to the conclusion investing into wisdom actually penalizes players :).

b) mind reading
Using mind reading is definitely useful and it´s a fun feature, but investing skill points into making it cheaper is useless in the Ego Draconis portion of the game - experience from enemies scales based on the level your character kills them at (say, killing a level 9 enemy with a level 6 char gives you 1000xp, killing the same enemy with a level 8 char gives you only 800xp) and mind reading in ED is not expensive enough to offset this. Not investing into it may seem like loosing uncomfortable amount of xp points at first, but iirc pretty much the only actual effect is that you´ll be 1 level behind at some parts of the game (but, again, with more skill points at the disposal of other skills).
In the expansion mind reading costs were dramatically increased, but that part of the game also features respawn zones which may be used to offset it - which isn´t worth it in my opinion, by that time you´ll be swimming in skill points anyway
so investing some points into the skill (or even maxing it via respec) shouldn´t be detrimental by then.

Gear which adds to these skills is, of course, useful.