When you go to settings and click save, the page doesn't reload and there is no feedback in the form of text that confirms the changes. Perhaps implement one of those. I know changes are saved instantly and the button is a gimmick, but it feels like one that doesn't function right now. Not the most important but still.
Log in
I know on one site I had, I've been reusing the same login form on every site I've ever made, the sign in and register button actually do the same thing. It's just that if you put in a unique username it's going to register it. Some people would hit register without anything in the fields thinking they needed to navigate to register. So what I did is I just deleted the login button and I would display:none their screen for a quarter of a second like a page load just happened.
That's just hilarious to me.