Is it OK to marinate the wrapped pork for a much lesser time?

Sure. I've done it by just putting on the rub and going straight to the oven. It's just the longer you marinate it, the deeper into the meat the spice flavor will migrate. But if you're going to pull the pork and mix the crust in with the interior anyway, you accomplish a similar thing. Hope you enjoy!

Thank you. I'm working on it now.

It's a dry brine, so I'd try to do it for at least 4 hours -- is this what you had in mind by less time?