Regarding the hub, there's no such thing as higher quality than a Shimano or Campy loose-ball hub. The Tiagra is just teensy bit heavier than an Ultegra hub. There are lighter hubs, but none that will roll smoother.
Bladed spokes would be more aero. Nothing wrong with that, I just thought you were going for economy here.
Spoke holes... hmm. I'm not familiar with that difference. Can you see if the old nipples fit on a standard spoke? Do you have the old nipples?
A quick search online, and it looks like the Vector Comp used standard nipples. I don't have a pair around to examine.