d) The level difference between old and new players which creates an artificial barrier between these communities.
Which is thoroughly solved with the introduction of new servers that only serve new players and not existing players. Which I believe Wint and others have mentioned here repeatedly.
There's no power differential between these two groups unless you WANT there to be one by rolling on an established server as opposed to a new server.
It is not logical to wipe existing player data because this isn't a new game. This is a rebuild of an existing game, and these players have put in their time and deserve that not to have been a waste.
As a side example.. Blizzard doesn't wipe player data between expansions.. this isn't strictly an expansion of FFXIV, but it may as well be.