Troll PC, effective character level of 8th Level. How many levels of Barbarian can he take? If I'm remembering correctly, they're CR5, meaning he could take 3 levels of Barbarian, yeah? How many feats would that character then have?
Also, costwise, how much would an Amulet of Mighty Fists(Impact) cost, and how much would it cost to also give it the properties of a Forge Fist Amulet?
For the first question he would have 3 levels of Barbarian unless you let buy off at 3 and 6 to drop it down to 3 Cr and 5 levels, you can reduce the Cr by half rounded down (so at level 9 he loses another CR and gains a class level)
He would get feats based on HD, so if he had 5 RHd and 3 Barbarian HD he would get 4 feats