+2 to hit might not be comparable to another attack, but -2 to theirs is comparable to not taking another attack. Which is always good. On top of this, they can only half move and have to waste prep to stand up.
And while there are always spirit control methods, you won't always have them, have them available, or take them immediately. Plus, racial talents like superhuman strength and such, CANNOT BE USED IN COMBAT. They require a stat check to be made, which are never made in combat unless something extremely specific happens.
So right there, most racials are out. In fact, all of them are but spirit control. None in the main book work on anything but stat or appearance checks besides that. Its also just +or - 1, which while helpful, is not the greatest thing ever at 1/round. not to mention requiring you to be human. Dragon lord has an equivalent, but faces the issue of taking an attack timing to use.
As for the others, those assume you have that style. Yin style's not bad, but assumes someone has what you need. Assumes you are arc slayer though.
Aura commandment is pretty good for a general feat. This one i'll give you, its just an all around good pick.
Power emission is great, but only works once per combat.
So the best you have on average if you aren't arc slayer A is to increase a couple dice by one or two once a round. If combat lasts more than say, 3 rounds, your spirit control severely drops unless you have a digital sorcerer or a divine talker.
There's a bunch of others scattered around the books, but in totality, they are a very meager portion of the entirety of what you can choose from, and often require you to take a specific race or style just for them. Magic weapons have 1. but that assumes you are using magic weapons.