That sounds like good suggestions. Who knows what the kids will think of sandwiches hand wrapped in waxed paper?You can buy wax paper sandwich/snack bags as well. Amazon has them in bulk. 200 bags for $14.99. They're easier than zipper bags to get sandwiches into. You can also buy paper sandwich bags.
Sometimes kids will think something is weird, for reasons adults don't understand. Sometimes it's the other kids at school that tease for something. Now, I'm not saying that kids will react badly to hand wrapped sandwiches, but if they do, then the ready made bags might solve the problem.