I don't think banning all NFE is a good idea, as that would mean we would have to ban Pikachu, Trapinch, Scyther, Vigoroth, and Clamperl for no real res=ason.
I was of the belief that for the purposes of this discussion the term 'NFE' means any Pokemon whose fully evolved form is BL or above. With this definition, adopting the 'none at all' policy would mean that every Pokemon would belong in the same tier as the fully evolved Pokemon in the evolution chain, meaning that Pikachu and Clamperl would be fine regardless.
Also in addition to the criteria you posted maybe something along the lines of movepool differences allowing for a different play style (an example of that would be Togetic).
I'd tread carefully with that proposition, as there is a fine line between 'allowed' and 'forced'. By this I mean, in the example you've given, there is nothing Togetic can do movepool-wise that Togekiss cannot do should the player desire. This means that using Togetic doesn't 'allow' the user any additional options over Togekiss.
On the other hand, we see that Togekiss has moves like Air Slash and Aura Sphere that Togetic cannot learn. These are moves that Togekiss commonly relies on in standard play, therefore you could say that Togetic is 'forced' to adopt a different style of play to Togekiss' common paraflinch strategy. The problem with that is the enormous subjectivity involved. Do we allow the likes of Wartortle and Ivysaur who cannot learn Earthquake? What about Diglett who doesn't learn Stone Edge? You could adopt the 'common moveset' argument, but again how you define common is incredibly subjective and will lead to disagreements.
















