A couple of quick comments:

One area of censorship I do support, however, to be clear. Attemtping to spread racial and ethnic hatred should be flatly "shut down" as in blacked out in my book. No reason to use the excuse of free speech for that type of human garbage thinking and language.
Yes, but only where this is supported by existing, tested legislation. Just because people don't like Islamists is no reason to close their forums. The First Amendment to the Constitution does not protect the sorts of things you're talking about, nor do the laws in most countries.

In particuarl I note of late sputtering on various Pakhtun websites (worldwide) against European national laws disallowing talk and promotion of Nazism and ani-Semitism...5 years in prison for such stuff. Fully agree with this specific style and type of censorship, as it has helped clean up Europe ever since WW II.
I'm no fan of that type of legislation, and it's also questionable whether it works. However, I would say that this is perhaps the exception rather than the rule. Also, citizens in those countries are very much behind those laws - there is a public mandate for them, and I therefore support them. There would not be the public appetite for most other types of expression, save for paedophilia.

Tim