I've never had a freezer bag or even a thin sandwich bag pop open up to 11,000 feet. It takes a lot of pressure to pop a freezer bag, far more than air expands in a few thousand feet of altitude. Try sitting on a freezer bag with stuff in it. If you sit down on the bag abruptly enough, the closure will pop open.
Vacuum sealing turns the contents into a hard brick, which you don't want. I try to get as much air out as I can, which works just fine. You can use a straw to remove a little more air.
The problem with a pinhole in the freezer bag is that it also lets air back in and lets water leak out when you rehydrate in the bag. If you're going to put garbage in the used plastic bag, the smell will exit the pinhole into your other food.