It also affects the passive regen limit, which I personally would definitely want.

Masteries in general could use work IMO. We're looking at 24 slots for passive abilities I would consider mandatory (Powermonger, Yogi, Strategos, Titan, Tribalist, Duelist), and that's at tertiary spell slot progression. Barbarian abilities feel very limited (again, IMO) until circle 100+ when you have enough abilities in each path to start choosing multiple masteries, and everything comes together nicely between berserks/forms/roars/meditations.

I'd like to see the bonus ranks dropped entirely in the interest of saving spell slots, and I'd like to see each separate function that comes bundled together offered as a separate mastery (i.e. Strategos would get turned into one mastery for roar area and another mastery for increasing IF bonus from kills). We could keep the ability tree model to differentiate them from magic feats, but I would also like to see them made available much sooner (i.e. roar area at 2 Horde abilities, more IF regen from kills at 4 Horde abilities).