Do the masks ever progress beyond 4 evolution points, or do you just get more different ones? That'd be my glaring question regarding effectiveness-- I'd worry about replacing an ability that advances in raw power as you level with one that gains flexibility but no power.
I go up to 6 evolution points per mask at 10, and 8 at 20. At 7, I get to have one evolution point active at all times, even when not in rage, and which evolution it is can be changed. At 15, I get 2 active at all times. I do have a bit less raw power than a Barbarian, true, but in this case the flexibility is good enough to be worth it.
On relevancy, I certainly wouldn't bother with Spring Attack/Vital Strike. The point of Pounce is to avoid the need for things like that.
If I don't take those three feats, where should I reinvest them?
The two options that immediately jump out to deal with the standard charge-and-pounce tactics, to me, are overrunning and flying. Overrunning breaks mook walls and can add up to a fair bit of damage, flying avoids all those irritating terrain issues. The former, you have two rage powers (Overrunning Advance/Overrunning Onslaught) and a handful of feats (Improved/Greater Overrun, Spiked Destroyer is amusing). The latter, you have a three rage power chain that culminates in flight with the new Elemental Blood powers. Unfortunately, Lesser Elemental Blood is a minor damage boost and Elemental Blood is pretty mediocre; you'd be looking at Electric Resistance 10. Greater Elemental Blood (Air) gives you a fly speed of 60 though. If you have an easy way of flying, probably not worthwhile... but if not, that could be a nice way to ensure your pouncing fun doesn't get interrupted. I do see that one of your Masks has a flight option, but personally I'd think you'd rather use your Masks to boost your offensive prowess, since this is still more-or-less a rage. That kind of depends on your GM and whether or not they like to shut down charge lanes often.
I think I did take Improved Overrun already. Can I even take a blood power? I thought those were Bloodrager only.
I am allowed to create my own masks, so I could take my Mask of Mists, drop the Shadow Form evolution, take a different 2 point evolution like +2 Str or natural armor, and have a mask that enhances my combat ability and lets me fly. Then, I'd be capable of both overrunning and flying. The one thing is that I can't change masks during a rage, so I have to decide if I need to fly when I first activate the ability.
I do have to admit, I'm not a fan of Reckless Abandon. Your goal involves getting in their face as fast as possible, tanking your defenses to do that (even if you are more flexible than the standard Barbarian in that regard) seems like a dangerous call.
What else could I take that aids speed or maneuver?