I really dig the races. Are those something you've posted in the past?

Half-Orc seems kind of weak compared to the others. The Orc Ferocity ability is really pretty meh. It will almost never trigger, and when it does it's nearly time to retire your character anyway, because you staying up and continuing to fight means you're still a target when any small number of damage will take you to dead dead. Working around that with something like making the Orc immune to all damage for that round is something you probably don't want to give out to a PC race at level 1 though.

I'm also not sure why you nerfed the Kobold's movement speed from 30ft down to 20ft. If you're standardizing the movement speeds based on size, then Dwarf should have been brought up and Halfling shouldn't have gotten the buff to 30ft. Kobold's slight build is cool and I love the ability to squeeze into smaller tunnels and get better hide checks, but is there any situation ever, even in your house rules, where a smaller weapon is more beneficial? If not, the line about being able to use a smaller weapon is extraneous and can just be removed.

On the topic of movement speed, while I like what you did with the Dwarf, could you maybe bump its move speed back up to 30, and if you really want to reflect its traditional slowness, reduce their run multiplier to x3 from x4? That way the Dwarf can keep up with anyone else in typical mobility, but isn't as fast in a sprint to get away. Keeps the theme while not being quite so crippling for a melee character.

Also, maybe switch the free Dwarf feat from Diehard to Endurance? Diehard as a similar problem to the Orc Special ability, while Endurance is very much in character for Dwarves, situationally useful, and a prerequisite to some feats that a Dwarf might be interested in (Offhand, Steadfast Determinination is a big one. But there's at least a dozen feats that use Endurance, and probably more prestige classes. Nothing that I'm aware of requires Diehard), thus saving them a feat tax.

It's mostly an RP thing, aye. Would it be worth it if it removed the penalty altogether?
It'd have a more demenstrable effect, but since the penalty you're offsetting is still mostly RP, how useful it is is going to vary wildly from group to group. I'd leave it with the penalty reduction as you have it, and tie some other perk to it to make it more appealing. (say let you expel two vestiges at once, or even just +1-3 uses of Expel Vestige, a la Extra Turning and the like).

If you get a result of 0 rounds, the ability is usable again that round, if you have the actions to do so.
Fair enough. I don't think most binders have the action economy breakage access to take advantage of that, but even having a 50% chance of your ability being available next round is a great deal.

...for some reason, I thought the psion had about 2 powers known/level. I'm not dropping powers known, but I can weaken Enervation again.
Yeah, that works. Leave Enervation as dazing, but keep your reduced power point loss from enervation maybe?