A bit more input.

4) The easiest way (least hassles) to get a Business (J) seat using miles is to purchase them outright - these seats come from the O bucket (that's 'Oh', not 'Zero') and are the most likely to be available at any particular time, but seats bought this way cost roughly twice as many miles as they would if you'd paid for an Economy (Y) seat and then upgraded, and you'll also have to pay the fuel surcharge in cash. So why would you do it this way? Because EK make it quite difficult for you to upgrade from Y to J. It's almost impossible to do it until 15 days before your flight departs, and it then depends on how many J seats are left for sale. Also, if you purchased an ultra-cheap Y seat from one of their special offerings, they won't allow you to upgrade until 24 hours prior to departure at the earliest, by which time all the D bucket seats (those J seats that you can upgrade to from Y class) may well have gone.