Longely I would think that its just easier to get the mouse location. Not a big issue
With the buttons, how many should there be? As I see it, we could have
- Replace the current tab
- Open in new tab
- Open in the background
iOS Safari gives you #1 but makes you choose betwen 2 and 3. However, I think all three have valid use cases and all three should be added. They just need different icons.