Hi, Starman:
I agree with Chuck. If you're interested in a soft, pliant leather, you should be looking at latigo or chrome-tanned leather. Trying to turn ordinary veg-tan into something different by over-oiling is not optimal. All you'll accomplish is creating a belt that's weak and prone to stretch, and one that weeps oil and stains clothes.
Keep in mind that a belt should have a good measure of rigidity, anyway. Belts are load-bearing and subject to stress. Soft leathers will stretch, or the holes will enlarge. Neither situation helps keep your pants up. As such, I'd steer clear of soft, chrome-tanned leather and probably focus on latigo. If you visit your nearest Tandy Leather Factory store, I'm sure the manager would be happy to show you all of the different kinds of leather and explain how each is used.
Good luck, and welcome to LW.net!
Best, -Alex