Two questions, one about spell mastery, and one about totem warrior

[Juton]

The Witch (APG) is prepared spellcaster like a Wizard, except a different spell list and uses a familiar instead of a spellbook (among other differences). I've found that familiars are a little more death prone than a Wizard's spell book, is there a clarification that a Witch may take the feat Spell Mastery? The feat specifically requires one level of Wizard to take, but was written before the APG came out when there was only one arcane prepared caster.

Second question, Barbarians can choose an alternate class feature called 'Totem Warrior', what do is do exactly? The PFSRD says : 'The totem warrior is based entirely upon his totem rage powers. In addition to the totem powers themselves, the following rage powers complement the totem warrior archetype (depending on the totem chosen)'. But I don't see any totems listed, is this referring to the spirit warrior rage power, is this just a label you can use to describe your barbarian or does it have something to do with the Druid's totems?

[Defraeter]

1) Spell mastery: for me, this spell is relevant to use of a spellbook. Witch have their familiar and hexes "at will"...
So, as GM, i don't give this feat to witch.

i think one feat very important for witch is Scribe scroll, because if the witch loses his familiar...

2) Totem warrior: it is only a "roleplaying" choice for your barbarian.
When he chooses a totem rage, like Beast Totem, lesser (Su) of the totem "Beast", he can no more take other totem rages (like Chaos Totem, lesser (Su) of totem "Chaos").
All the totem are linked to rages powers with "totem" in their name.
Remember you can stack archetypes if the requirements are not the same...

edit: the rage powers listed under "Totem warrior" p79 are just advices for a player who want to play "in the spirit".