"However, your forgetting the first thing - UA does charge extra for E+. It just simply waives that for it's elites. If you're a non-elite, you must buy up to those fare classes that are eligible."

I believe that this is not actually the case. I believe that anyone checking in at the airport can request them. Only "elites" and full fare passengers can pe-select them though, whilst 3rd World Traveller Plus is only available to those paying for WT+ tickets

Dave