A few idioms I don't fully understand

[Czarny]

Hi!
I've been translating some comicbooks recently, and I a few idioms came across, that I don't fully understand. I think I know their meaning intuitively, but I want to be sure :)
So those are the idioms:
- to be out of one's depths
- to be someone (something) born and bred
- to strike a nerve
- to take something on the chin
- beat someone somewhere (it's got something to do with meeting someone, I think)
- to cordone some place off

Thanks in advance!

[Tdol]

1 too heavily involved
2 100% that thing- a Manchester Uniterd fan born and bred- all his life and forever
3 cause a negative reaction
4 accept a punishment, etc, directly
5 get there first
6 close a place to the public, like when the police block a road after a crime

[Ouisch]

1 too heavily involved

Just one quibble (sorry, tdol ) - "to be out of one's depths" - it could be a UK/US thing, but I've always understood this to mean something that is beyond one's expertise, something that is difficult to comprehend: "I was accepted to law school, but I was so out of my depth that I dropped out after one semester."

[Tdol]

It can have that meaning too-I should have put it.

[JPE]

think it only has Ouisch's meaning, at risk of being pedantic.