Mmmh, have you tried rebooting your mac? I know it's not common, but a full reboot might solve it. Maybe there is another instance of 0 A.D. you need to kill. @Langbart have you ever seen this?
EDIT: Logs would help.
Blender messes up animations when importing old models. Safest bet is reexporting everything. Sometimes you need to remove custom properties from every bone. I made a tutorial somewhere.
Interesting.
I don't know for sure, but I'd say it didn't exist when this forum was created, nor when we were using the previous software. It has to be noted though, that IRC has been quite a standard in the FOSS world.