Currently, some actions spawn confirmation popups, which slows down the workflow and adds confusion if the action was already performed or not. We've solved this problem already for things like the Remove Doubles tool, which immediately performs the action, but then displays a message in the Status Bar to let users know what happened.
There are several prompts we could remove completely, in favour of showing a message in the Status Bar.
For example. there's no need for a Save popup menu with no options other than clicking. In fact, this is a usability issue, because users might think they have already saved when in fact they have only opened a dialog. I've seen users lose work because if this behaviour.
So, rather than showing this when you hit Save, which requires an extra click every time:
We should just save immediately and display a message in the Status Bar, like so:
The same goes for things like deleting. When hitting the Delete key, rather than showing a popup that you need to dismiss, we could just use a warning color in the Status bar with a message:
It's both easier & faster, and with the message UI, we communicate to the user what is going on.
We could keep the X key behaviour the same as now, since it's much easier to accidentally hit than the Delete key.