I tend to assume the racial powers etc are some sort of gift from the Divines, and the daily limitation is imposed by them. I rarely end up using them in vanilla, though my first Imperial character used the Voice of the Emperor a fair bit (once got chased indoors by some bandits I hadn't noticed, used it, watched them walk out, very satisfying, then I looked around at the mess it had made of my decor...) I'm currently playing Requiem, which changes them, e.g. Highborn now means my Altmer has unlimited Magicka for 60 seconds (incredibly useful) vs better Magicka regen in vanilla. I still forget I have it quite a bit, and my Altmer has a fairly large Magicka pool anyway, but I'm starting to use it more. I'm also starting a Dunmer and a Bosmer, have to see what their powers are.