I see where the minimum Intelligence plays into this, but how does the psychological problem?
And I would probably make the 2x Learning Rate an Advantage for Actions rather than a generic modifier. Maybe +4CL? It's pretty powerful; you'll be doing whatever you've put it into a lot better than everyone around you in a much shorter period of time. Maybe more than +4, but definitely +4 at a minimum.
2x Learning Capacity seems a little trickier. Looking in the guide, there are a few characters who actually surpass this maximum of 9 (I don't remember any off the top of my head, however), but for the most part, Actions can be combined to allow for more space. Maybe a 10w mod for every extra Action you can start with (I know that goes against the catch... but its just a little thought) and a 7w (8w?) mod for each additional Action you can add by lines? I price the second one lower mostly because of that first step for gaining the Action; if it's anything worthwhile, it's going to take quite a few LoE to build it up to be learned with the notion that 1CL=10LoE.
Psychological problem is there, because those who have them tend to see the world differently. Sometimes, they can understand the world around them better than a sane person, although they still have trouble coping.
The modifier for 2x Learning Capacity does sound useful. It prevents them from learning those extra skills too quickly (Unless they take 2x Learning Rate too), which would keep it balanced.