PLEASE don't have unobtainable achievements in the list
Currently there are at least 3 mutually exclusive achievements in the list (Leaving Limsa Lominsa/Gone From Gridania/Out of Ul'Dah), meaning only one of the three can ever be achieved on any one character.
As an achievement hunter (and I know there are others out there) it ruins a lot of the fun when I know I cannot completely check off a list. I am concerned that because of the already existing mutually exclusive achievements, that in the future there will also be achievements that are unobtainable to some players due to something missed or old content.
CONT BELOW
PLEASE don't have unobtainable achievements in the list (part 2)
"Other Games" have done a very good job with this. Nothing is mutually exclusive (above achievements could be combined into one "Leave Home City" achievement), and old impossibly unobtainable achievements are lumped into one category of their own (Feats of Strength) so they aren't obliterated, but aren't considered in the obtainable list either.
I know there are some people who don't care about achievements or achievement hunters, and that is their prerogative. But I would think that the majority of people who like going for these things are going to agree with me, that the entire list needs to remain complete-able or it doesn't remain fun.