It means submission which is generally understood to be submission to god and that means peace. But of course, as you said, that everyone has different takes on it all and there are sects that believe everyone needs to submit to God under islam's terms and that often comes with violence. Everyone should believe in God in the same way. The very same thing happens in Christianity because God says that everyone should be saved and believe in the father, son, and holy spirit. This is why we had the crusades and such in the first place. Convert all non believers...through violence, if need be.

I believe every religion is inherently the same. Only the stories change. Each one preaches peace, love, and unity. Certain people decide to taken specific messages in specific ways. They don't even necessarily twist the words around. They just focus on different aspects.

So i guess my point is that these religions are not inherently preaching violence. And if you do say that one religion preaches violence, you should acknowledge that the others can be read in the same manner. So saying "Islam is bad but Christianity is good" for this reason is being ignorant, either willfully or not.