Should and Ashkenazi such as myself learn Yalkut Yosef and Kaf HaChaim, Sephardi halachic works, or should I not bother as the halacha wouldn't apply to me?
I don't see how it would hurt to learn them, as long as you aren't sacrificing learning time you could be using to learn more relevant halacha. Learning Sephardi halacha may not be useful to your own practice, but it may help you in understanding someone else's practice.
Consider this - do Ashkenazim always pasken the way the Shulchan Aruch brings halacha? How about the Mishneh Torah, or even the Gemara? Yet would we throw out learning these works simply because we don't pasken like them? Heaven forbid.
I'd hardly say there isn't any "point" to it. As I said before, I just wouldn't sacrifice learning time you could be using to learn more relevant halacha in order to study them.
For what it's worth, I, an Ashkenazi, have done a little reading myself in Yalkut Yosef. It's helped me out before in understanding Sephardi practice, and in answering a few Mi Yodeya questions. Conversely, I've known many Sephardim who've learnt the Kitzur Shulchan Aruch from Rabbi Shlomo Ganzfried, even though all the halacha is like Ashkenazim. (Of course, nowadays you can even find a Kitzur Shulchan Aruch with notes on Sephardi halacha.)
If your goal is to learn "plain old Torah", or you are studying in order to Pasken for Sefardim, this would be a useful resource.
If you want to learn it for the purposes of Ashkenazi Pesak Halacha, consider some of the alternatives mentioned here.