So I've looked through the incantations, and I've got a couple of thoughts. Mostly, some of them seem counter to the project's stated goals, and may be clearly better than other choices. In particular:
Corrosive Touch has an ability that's specifically useful in combat, which is odd considering the goal. While the level you get it at means you'll rarely be encountering non-magical armor on any foes you care about, it might be a good idea to remove that use just to make it fit the concept of incantations better.
Rite of Return provides a get out of death free card under limited circumstances. That's fine, but it's also a combat buff since it means you suffer no consequences from a death. You might add a 1 minute delay between death and resurrection to resolve this, since that should take you out of combat and still allow you to return in a timely fashion from a character's perspective.
Invade Mind doesn't go against the goals, it's just insanely good. This is a consequence of modify memory, but you might want to institute a limit on how often it can be used on a single target since the optimal first use is to implant a memory of yourself being hired to perform some magical healing or enchanting service on your target (making every further use of this ability expected and thereby making everyone you can get to fail a single Will save your eternal mind slave).
Fortify Mind provides an excellent combat buff in the form of immunity to mind-affecting effects. Since its duration is 24 hours, I'm not giving it a pass on being non-combat like Illuminating Gaze. You may wish to remove that immunity and leave just the immunity to divinations, which isn't nearly as impressive in combat.
Freedom of the Storm provides another combat buff staple, in the form of freedom of movement. Again, this option clearly stands out for the combat optimizer. You might encourage its uses primarily in non-combat situations by making each use of free movement require a standard action before proceeding (so you could use a standard action to automatically escape a grapple, or allow your next move action to proceed normally underwater, and so on).