1) Can Windows 7 be installed or do I have to go with Win 8 which I hate more than Win ME? But I hear that keyboard and mouse and Wifi won't work during install because of drivers not installed so..... 2) I am not considering the new MacBook with the one USB-C port and M processor. 3) I was thinking getting the MacBook Pro, but with the upgrade "Air" I was thinking the 13" might be good. Since I will be using two OS' it looks like I would have to pay the $300 for the 512 GB upgrade. Also do I need to upgrade the i5 to i7? 4) Using Windows for heavy Excel and database work. MacBook Pro or "Air"?