However – Left-clickable and scrollable are useless.

Right click and double click are indeed barely discoverable for most users, and for that reason considered bad practice – I don't agree, and think such explorations are a must if we want to be able to create rich web applications. A context menu is a huge benefit in desktop applications, so we should be eager to implement it on the web.

But like Michael said, a typical context menu would work almost anywhere in the page, so the icon again becomes kinda useless. And I don't agree about advertising those features to the users using banners, default tooltips and such – This is poor usability.

We need to continue thinking about this solution. It is a step in the right direction, but there are more steps to be made.

All good points. I wonder if taking this to the browser level in the form of a plugin might be another option. More advanced users might then potentially disable this, or it might get automatically disabled on its own for sites that are visited frequently (where the interactions are already learned). Taking it to the OS level would probably be better, but might require more negotiation?

And I am also liking the idea of using a real mouse symbol to convey these actions. Could be more intuitive. Agreed.

Wireframing – that's a better idea for application I think.

But in my opinion there is another use for this idea: its ideal for Wireframe-Dummies or, like said before, tutorials. If you have to to show a customer, how his application or website will function when ist ready, these mouse-icons are a good way to do that – even if there is no degin in the wireframes, like it should be.

So I agree with Pierre Foucart: Show this idea to the Axure development team! I'm not yet using this wireframe-tool, but I am looking foward to use it, just waiting for my boss to buy it…