Yes you can freeze cooked pork ribs just make sure they are properly wrapped and then heat them up when you are ready to eat them. Because it is pork, you need to make sure that they are properly heated through before eating them. If they were grilled add a little water to them and Bam you're good to go!
I think that you can but close it firmly and the wrap it firmly in cling wrap tightly to prevent freezer bite.