I've proposed roar changes before. I'll restate them:
Roar does a VERY minimal affect mastered, at 50. I've gotten detect magic and looked at the mob. It is useless versus any decently armored char.
Make it like a shaman spell that acts like a disarm, "it scares the opponent into dropping his/her weapon"
or
Make roar automatic when raged
Make roar affect like hysteria or fear
At the very least just upp the current affect to something substantial.
Yes, berserkers are definitely lacking. I agree, the path of devastation needs to be toned up. Maybe more hit/dam? Maybe make the bloodhaze happen more often? Maybe even give raged berserkers with path of devastation the "fast" flag.
I also think raged path of devastation zerkers should be able to weapon/shield cleave ANY weapon/shield regardless and given a HUGE boost in succeeding while raged.
And panic seems to be more of a drawback than a perk. I think it should be looked into.