http://www.smogon.com/dp/tiers/ -- So NFE does exist, or am I taking you too literally. Re-reading, you could have meant "NFE" was never played, in which you would be correct.
I like your final proposal X-Act. It is nice and simple and gives us a place to "put all the crap" without having to worry about it. He isn't suggesting 5 balanced metagames, Lemmiwinks, Unter would not necessarily be a balanced metagame, more a place to put everything else, from say Farfetch'd down to Caterpie and friends. I'm sure people could play it if they wanted, hell if there was enough calling for it we
could create a tier out if it, but that is not necessary.
As for this terminology, I don't really want to go to Tier 1 / Tier 2 etc... It seems just a little too charchterless. Although it is practical, I think a sensible middleground can be found. I wouldn't mind seeing something along the lines of: Uber, OU (or Standard), BL1, UU, BL2, LU, Unter. OU, UU and LU would all be tiers that we create through whichever assigned process, desinged to be balanced. I labelled the BLs 1 and 2, simply because they are just Ban Lists, and will likely be very small. We could potentially call Uber BL1 and the other Ban Lists BL 2 and 3, but again, I don't want our tiering system to completely lose it's character. I named LU (Lesser Used) so, because it would seem silly to have a "Never Used" tier
above another tier. Unter would simply be "where we put everything else."
This prevents us from having a huge NU tier, and allows us to create a balanced metagame, with it's own proper tier list. Any Pokemon that don't make that tier list probably won't be worth using anyway, simply because limited movepools will result in there being few usable tactics left.