Barb past life feat

[babyairl]

Ok so im Tring my barbrian into a 12figther\6barb\2rogue
Or maybe a 14figther\6barbrian.
But I will have barbrian levels, so my question is:
If I take the past life feat, and wont have barbrians levels.
Will I still get the benifits? the hidden ones that is, the +4 str\con when rage, and extended rage?
Or do i have to have atleast 1 level of barb for it to work?

Oh and if you can, which will have better dps?
14figther\6barbarian?
Or
12figther\2rogue\6barbrian?

[Relenthe]

you need a lvl of barb. and 13 and 14 fighter do nothing but just a feat, so 2 rogue is more dps