I think my primary two suggestions would be this:
#1) More options to USE Gates and/or Mastery! Adventures are the meat of the game, so it can be a bit disappointing to discover that you can almost never flex your forbidden muscles in them. Discreet use of the forbidden arts could provide some interesting alternative solutions. The capacity for teleportation in Gates in particular strikes me as pretty utilitarian.
#2) More (viable) options to develop your Familiar. The Familiar system feels a bit unfinished right now. Unless you've taken Zoology as a course or at least trained it so thoroughly that you get Improved Familiar Handling, improving your Familiars skills is always hideously impractical as it stands. Improved Familiar Handling almost makes it competitive, with the ability to train four familiar skills at once, but even then you have the problem of your Familiars attributes being kind of mediocre and hard to increase. There's very little motivation to ever train or use your familiar when you could instead train yourself.
Edit: On the point of number two, I think my suggestion would be some kind of system wherein a higher level of Bond lets your Familiar use your own attributes in place of its own (your Finesse, Fitness, etc) to some degree or another, so that the Familiar doesn't fall behind in usefulness quite so much.