I don't know how the Twighlites don't bother the other Sorcerers, mine bugs me and I try to desummon it every time I go to town. It would be a simple thing to despawn them as people enter the bank.
However what really irks me are those pet spider tank things. In the bank I go into all the time, I am frequently stopped by them. I have to jump over or move around them after I bump into them. Can't see them because of the crowd of NPCs.
I think I remember them saying in a thread somewhere that they are working on removing collision on all pets, outside of enemy pets in Cyro.