One recent event you forgot to talk about in detail Maelstrom was the topic of this thread.
ATF recommended FFL's be revoked for bookkeeping errors that the Court held were (1) unintentional and (2) were reasonably trying to be procedurally corrected by the FFL's.
That tells us that sometimes the ATF gets overzealous in their mission.
Overzealousness can occur anytime, it has nothing to do with past specific documented governmental abuses that you cited in your examples (i.e., in an attempt to discount and riducule members' concerns).
It is this overzealousness that has many people worried about the ATF IMHO.
I've personnally have had no problems with the ATF because I'm not an FFL holder, etc., but there are many stories out there where they do appear to be overzealous on too many occasions IMHO.
One example is the topic of this thread.