Nice observations , vishal.
Yes, in Vista , to clear 'recent items list', just right click on it and clear.
Also for your point no7, there's 'switch between windows' in the quick launch toolbar, so that can also be used. Yes that's a good tip to use ctrl key with alt+tab, but some may find it inconvenient the key combination, so this shortcut on quick launch toolbar is there. And instead of clicking, one can also use win key+the numeric postion.Moving from left to right they are numbered from 1. So if its in 3 rd postion , it'll be Winkey+3 and so on.You can assign 10 such shortcuts there. Last one will be Win+0
Also one will find that there's no menu bar in explorer. So to get that, just press Alt. Its a toggle key to make it show and hide in Windows Explorer. If one wants it to be always displayed , then click on Organise->Layout->check menubar.
Also one more thing , Winkey+spacebar will bring sidebar to front. (if your sidebar is not always on top)
Also as you said to open command windows here in your point 1 is also very handy.