If you really want to hurt your brain while deciding what to do, you can. But, if you look at what 'things' contribute to moisture in the basement, you should be able to answer your own quesion(s).
For example, if you have a below-ground basement, even with Drylok painted on, you might want to hang a vapor barrier as a precautionary measure. Then, on the other hand, if your basement is totally above ground, then maybe you don't. But if it's half-above and half-below ground, then maybe you want to 'vent' the lower portion INTO the top portion to allow vapor to escape. Sooo, in short, analyze your situation and the answer should come easily - instead of beating your brain up. The facts, man, just the facts. :)
Here are a couple of links that might help you. I, like others, see the barrier installed all the time, above and below grade. It's just a practice. BUT, I live in SE PA; not the desert SW. 'Things' are done differently in different places. Look at these links: HowTo Basement Finishing and Finishing a basement
My best to ya and hope this helps.
PS: After this afternoon, I won't be back until Monday ...