I agree on both fronts. Also, I feel that there needs to be more hammer-involved animations. As of now you only see him use it if you invest in that specific ability (ok so most people use the hammer smash but what if its not useful come release?) Otherwise he's just holds it to his side and slaps units around. Maybe when he crits he'd swing the hammer instead? Sort of like the the different grunting sound effect you'll hear in WoW when you're about to land a critical.. 

Its fun to be a rook fan

Well yea thus the whole "crits, not hits" thing, although if you feel that even that would look bad on minotaurs because they're not flying off the screen I would understand as well. During the later stages when he one-shots many of the lesser creeps you might run into the same consta-hammer problem too. Too much of the hammer is a bad thing, although never using it at all due to skill choices is bad too.

yeah.. alternative attackanimations would be cool, specially for melee heros. Caster/Ranger mostly got a special missile .. there's not much room for alternative stuff :/

I agree that the hammer seems to be underused. I propose that if it continues to only use the hammer as often as it does now (very rarely), then the hammer should instead be "summoned," suddenly appearing in his hands for the hammer skills. Of course, since it was summoned, it would have to glow yellow like the rook's hands (they might only glow with certain buffs; I'm not sure), or have some other indicator to show that it was special and not just a regular hammer that suddenly appeared.