After over 8 weeks, my bathroom remodel is starting to come to an end. My contractor has fixed the many quality control issues I pointed out to him. Up to now. The picture below shows one side of the vanity under the sink. It doesn't look finished to me, but my contractor indicates that when the J-box is covered it is perfectly acceptable. Am I being picky? Does this fall into the category of generally acceptable work in an area that is out of sight? Or, should I insist that it be finished properly?

As you can see, there wasn't much attention payed to laying the drywall behind the sink; the holes were rough cut without finish, showing studs and insulation, and the seams weren't taped. A large section of the vanity back was cut. We are concerned that critters might go in and out and perhaps even make their homes back there. I suppose that expansible foam could be used to fill the gaps. Would that make things right? Any insight you could provide would be appreciated.