Rooster Fertility and Age

[chickenreferee]

Is there a prime age when roos are most fertile?

I read an older post that recommended plucking or trimming the feathers around both the hen and rooster's vent area to increase successful insemination on heavily feathered birds. Does anyone find this helpful?

I'm interested in raising standard cochins and my rooster is 3 years old now. Should I be looking for a few younger cockerals to trio up with hens or will Charlie be ok to start with?

I know there is more to this than can be answered in three questions, but I just had them on my mind and thought I would start here.

Thanks~!