What jobs are available to Theoretical Astrophysicists and where are they most commonly located?

Well, you could end up in my field (Data Science) - I've met over a dozen PhDs in astrophysics playing the predictive analytics game. My brother in law is a team leader at Google and 4 of his direct reports have PhD in astrophysics, now they are Java programmers.

To obtain full time employment as an actual Astrophysicist you would have to be (a) brilliant and (b) lucky. And honestly, lucky is probably what you need to be the most.

I'm not saying don't do it, because all the ones I know enjoyed their time in school, but the reality is, you will more than likely end up building predictive analytical models.

The short answer is, "There aren't any." NASA funding has steadily declined, and they are the only people who ever really paid for that sort of thing. My PhD is in space and atmospheric science, and my group leader used to be head of research for NASA. He was the ONLY purely theoretical astrophysicist I knew, and he only accomplished that based on his past research victories. Not only will you have a very hard time finding an academic position in astrophysics, you will have to do a lot of research even if you do, and that's after around 6-8 years as a low-paid postdoc (read: grunt researcher) or adjunct lecturer. And industry doesn't have a lot of positions for astrophysicists at all. I left the field. I'm back doing software, because at least there's current and future jobs in that field. A bachelor's in physics could lead somewhere, assuming you followed it up with at least a master's degree, and a dual degree with astronomy can't hurt (except in cost and time), but I'd recommend against your plan as it stands. Sorry.