Answer Questions:
1. It only applies to the shaken condition.
2. The attacker must make a Perception check against your Stealth Check. If he beats your check, he cannot see you and cannot attack you.
3. The spirits are very visible and having the totem spirit activated is like having a searchlight at night.
4. Concealment and Miss Chance are rolled seperately
Im not entirely clear what the intent is. If your stealthed you are no longer "visible and raging" This also seems like a lot of work just to do the shaken condition.
Im pretty sure an attack that misses due to concealment is still 'an attack against the barbarian' if your not actually int hat square it likely is not an attack against you.
3 and 4 what Warboss666 said.
This doesn't just make them shaken. It forces them to attack you. The problem is they have to keep trying to attack you even if they don't know where you are or be forced to find you.
By my reading the shaken is a secondary effect where you force them to attack you. So the thing is I'm basically forcing them to attack me but in order to attack me they first have to find me. Until then they basically ignore everyone else because they have to attack me.
I don't see how you read it that that have to ignore everyone else if they can't see you.
If they can't see you, I see only three ways to interpret:
1. They can't attack what they can't see, so they act normally. Not exactly supported by RAW, unless the being visible and raging requirement is for the whole power, not just the shaken condition, then it's 100% supported.
2. They have to spend two move actions a round searching for you. Not even remotely supported by any interpretation of RAW.
3. They must attack you, but they can't. Paradox ensues and halts combat. Players retire to living room to watch DVDs. Not contrdicted by RAW, but common sense urges us to find a better solution.
I'm a big fan of Occam's Razor when it comes to interpreting RAW, and option 1 gives such an easy out, it's silly not to take it. Especially, since this wouldn't be the first poorly worded rule.
First after re-reading IT I see better what you are attempting. But i think this is a case of a poorly worded ability.
First the way it is worded, They basically will never want to stop attacking you.
Ie it says 'the target remains shaken as long as the barbarian remains visible and raging or until they make an attack on you' basically the only duration ender it has is for the shaken as written you can use this in a bar fight and the guy will be hunting you ten years later.
Basically im pretty sure this power is supposed to basically work like a mark from 4e.
You do the demoralize, they are scared and upset. they can either attack you to remove the penalty or attack somone else. the power gives them an incentive to attack you.