The spice rub helps the outside of the roast get a nice bark to it, it won’t be as crisp as smoking the pork but it works great for slow cooking.
You do not have to heat the meat in a pan, but personally I think Carnitas need that crispy edge. It’s worth the few minutes it takes to do it.
You can also use the meat for making sandwiches. Personally for Carnitas we like making tacos with them.
If you want to cut the sugar content of this recipe omit the Coke and use water, or vegetable broth. We enjoy the sweetness from it; it’s a nice counter balance to the spice and acid from the citrus.