2. Only a concern if you think that everything has to be done from the start screen/MetroUI. Everything feels just as it did in Win7 from the desktop in my experience (except Win8 is a bit faster).
3. Once again, only a concern if you intend to only use Metro apps. Windows on the desktop work just as they did in Win7 and multiple instances can be opened with a shift-click on the taskbar or right-click -> click on icon, just like Win7.
Honestly, Windows 8 has been my daily driver since consumer preview came out and after a little time acclimating myself to some of the new nuances, I found myself feeling much more productive in Windows 8 than I was in Windows 7. However, maybe that is just me and I pick up on newer UI/UX better than all of these people that have been complaining and put in the time to give it a try.