My biggest annoyance: letting scripts control the history. I can imagine that someone thought "oh it'll be nice, you can use it for pages of an app". But the reality is that people are not nice and it gets used maliciously all the damn time. It should not be allowed.

The web should be a method of delivering documents exclusively, and be limited to the kinds of things you can do with other computerized documents (the basics, but also Audio, Video, Animations, hyperlinking, etc.)