No, because it is
not a proper
nou
n.
It does not have to be capitilized.
yes
Yes, the title "World Wide Web" should be capitalized. It refers to a specific network of information that is accessed using the internet.
No, except at the beginning of a sentence because it is n ot a proper n ou n.
It is what newspapers and publishing houses would call a 'house style' issue. I have seen the odd place that capitalises 'Web' but most places don't. The Associated Press Stylebook (in part) and Chicago Manual of Style both disagree with the answer given above. "Web" is part of a proper noun, and as such is capitalized.
No. It's not necessary.
No it does not have to be capitalised.
It varies depending on the dictionary you consult. Because it's derived from the proper noun World Wide Web, it started out as two words with Web capitalized. Webster's dictionary still lists it as such. Oxford dictionary lists Web site first with web site and website as variations. The American Heritage dictionary lists it as website with Web site as a variation. In everyday usage, website is far more common. You could defend either spelling, but for formal circumstances (like a school paper), Web site would be the safest.
Yes, "World Wide Web" should be capitalized when used as a title because it is a proper noun referring to the specific decentralized system of information sharing on the internet created by Tim Berners-Lee.
YouTube is not a web browser but a website. Web browsers intercept YouTube as a website.
A web page or website are hosted on Web Servers
the web site's Digital Certificate