All of these problems have to be dealt with. There is many more people with offensive emblems than hacks, but hackers will definitely get more reports. An offensive emblem may get one to three reports a game(I personally rarely look at emblems, so have only reported acouple times). Hackers get reported by every player in that game, so I would expect the hackers to easily get weeded out. Besides online system will be pretty tough to hack, so we may not even see any actual online hacks.

As for the nazi symbol, my suggestion would be to not use it. Even though you may claim it as something else, Treyarch isn't going to ask your opinion and no one knows the consequences so far, so you could be risking a ban or reset so you can have that as your emblem.

I have got messages for my emblem being offensive(picture at bottom of my signature under the +repifiwashelpful thing) and I really don't see why it is. So if I get reported to the level that I have a confrontation with Treyarch, well idk what I would do. They would probably let me go.