One thing's for sure, prodigy is not worth even +1LA.
Guardian spirit is crap as well, since you eventually get rings of protection, superseding its benefit.
In fact, I think the LA was based off the assumption you get them at 1st lv. If you had the benefits scale (ie: start off weaker, then slowly improve), the LA would drop dramatically.
Alternatively, make them cost a feat (the most I would pay for the weaker traits).