Thoughts forwarded regarding familiars in the past:
Make them personal (a la companions) (being worked on)
Interim fix: adding time
Interim fix: adding choices
Well, I'm forwarding another notion. Incorporate some of the ideas included in Whispering Willow (605) - make it so that a certain skill expands the area of operation - in short, inter-realm (familiar) movement. Example: with X ranks of X skills a mage can glance up with weary eyes from his cauldron at the Wizard Guild in WL, see a friend die in the Elven Nations, then send his beloved familiar there to offer some semblance of aid. Extra RT could be added when it comes to the familiar's possible actions in such a situation.
Familiar Gate would not be a part of familiars being able to move inter-realm, of course.