For 3. Shift+tab goes backwards through the form.
For 4. While still on the find dialog, F3 and shift F3 toggles through tne entries forwards and backwards respectively.
For 8. Ctrl+T applies to IE7 too, and ctrl N should open a new window in both browsers respectively.
For 9, Ctrl+W closes the tab in IE7, and closes the window while on the last tab.
For 10, now in Firefox 3, ctrl++ and ctrl+- zoom in and zoom out of the page respectively, and saves it for the page you are on.
Now for some of my own.
Alt+Left Arrow key goes back on a page(Backspace goes back too), while Alt+Right Arrow key goes forward.
In Opera and Firefox, ctrl+shift+T reopens last closed tab(ctrl Z should do the same in opera too, but only if it was the last action).
Ctrl+E should focus the browser's search field if there is any.
Hope it helps
