You could argue this sort of issue already exists. Most elemental casters are Dragonborn for the MCL bonuses and DCs.If we are doing Planescape, I'd rather have Genasai. I guess there could be an issue of power creep if you had racial trees that gave elemental bonuses to spell casting, for example, all ice druids would suddenly be water Genasai. If care were taken, this is an interesting race, very magical, good appearance, and fits the theme. I'd prefer they not add psionics to the game. It will invariably be overpowered to start then will get nerfed 6 months down the road. Why go through that?