Alright, I'll admit that my first impression was a little overly critical of the animal companion and feats. But Threaten did have to go, and at least something else.
The original version got Toughness and maybe Endurance in place of Fast Movement, a fighter feat in place of Indomitable Will, Great Fortitude and maybe another fighter feat in place of Trap Sense, a third fighter feat in place of two or so Rages per day, Mettle of Fortitude in place of another two or so Rages per day, heavy armor and tower shield proficiency in place of any other Rages per day and some of the Greater Rage benefits, and an Animal Companion in place of Mighty/Tireless Rage benefits. Plus Threaten on top of that.
As it is, I still think a full-power Animal Companion is of more use than Raging, and it doesn't carry any of the drawbacks of Raging. Having a dire bear, megaraptor, or what-have-you with extra hit dice to fight beside you, flank with you, soak up damage for you, and dish out more damage with you is handy. Not to mention any of their non-combat uses (even if for nothing else than scaring the bejeezus out of other people).
Now, with Threaten and the extra proficiencies gone, it's certainly closer to balanced. I'm still leery of them getting quite as many feats, but at least now they're close. I would just ditch Toughness and maybe Great Fortitude now.
Regarding the alignment requirements: I"m not objecting to it from a flavor standpoint, and it's certainly no more restrictive than a barbarian's (being chaotic doesn't deny you access to anything that being nonlawful wouldn't have; it's still just no access to lawful classes like knight, monk, or paladin; though I can see the argument that it just may, slightly, inhibit some rare munchkin cleric or PrC combo that requires a lawful patron deity). It's just that the class doesn't seem to have any need for chaotic alignment in order to function, and has no drawbacks for changing to another alignment. They don't have Rage and they don't lose anything for becoming nonchaotic; it's not even stated if they cannot advance further as a Survivalist that way (though it's a fair assumption).
Setting-wise, I just don't see much need for a whole base class to represent one small group. Base classes are supposed to be more general than that. And what's to prevent people outside of Clan Zaitsev from becoming Survivalists? It's not like it's impossible for a member of Clan Zaitsev to turn traitor or become an exile or adopt someone outside the Clan or do something else that would result in people outside the Clan learning the same kind of training.
Nor any reason why other wilderness tribes or something wouldn't potentially develop Survivalists from similar conditions in their environment and lifestyle. Plenty of people around the real world have traditionally relied heavily on certain animals and formed close bonds with them; how do you think we got all these innumerable breeds of domesticated cats, dogs, horses, and such, many of whom bear only a vague resemblance to their wild kin? Horses and dogs have been especially important in many places.
Besides making a whole class for them, there's always the option of using regional feats or ancestor feats (as detailed in the Forgotten Realms Campaign Setting, Oriental Adventures, and Dragon Magazine), and/or racial substitution levels (as described in Unearthed Arcana) to represent a particular culture's background and training. And as mentioned, feats like Wild Cohort can help. In any case, it's your game, so if you really want to distinguish this Clan Zaitsev with their own base class, that's up to you.