It would be really great if any javascript binding could be turned off in about:config or it's equivalent in other browsers. It's not really a solution, but would bandaid a lot of bad design which I can't see any legitimate use for (like scroll-hijacking).

I guess you can already overwrite any existing function with your custom non-function with userscripts, but that seems quite hacky and non-portable, since most mobile browsers don't really support extensions (Firefox does, but only a small subsection)