Yea, we can come up with all sorts of rationalizations like the one you stated, which works well, but we really need a explicit ruling on whether or not we can increase the Force Rating, and then we can use options like yours to create a supporting history, if needed, to work with the DM.
That explicit ruling is in the books. Force rating is a talent, and there are only two ways to purchase it. Once each. Thus a max of 2.
Anything else is a house rule.
