I agree, you're a mirror of your workplace

Usually yes, but there are exceptions

I think that's bit too extreme

I don't agree with this at all

getting into physical altercations

being racist/mysoginistic/homophobic

drunk posts on social media

illegal behaviour

drug addiction

murder

racism/neo-nazism

physical/mental abuse

Yes, i definitely can. My job doesn't define me

Not sure, you can't completely change who you are

I can't do it, who i am reflects on my job

You should try to keep a balance between the two

Yes, i would have a moral obligation to do so.

How questionable? It depends on the content.

I would wait to see if the posts get worse and then react

No, what they do outside the workplace is not my business.