if somebody from the u.s traveled to England

I think someone traveling to the US from England should be more concerned about their safety than the other way around.

Certainly, there are extremists everywhere, but in general they are friendly to tourists or outsiders (can hear bad things, but they exist everywhere)

They would be absolutely fine unless they are called Trump in which case they would be laughed at for their stupidity

Of course. What are you concerned about?

Depends on where you go and how big an asshole you plan on being to the natives

Perfectly okay, we have road rage and knives no guns.

I had no problems.

Yesss

No. Expect to be made fun of