The composer of the music and/or the lyrics will need to be paid for their work whenever it is performed by someone. This process is known as performance rights. Each country will have their own organisations familiar with local legal requirements such as PRS in the UK or ASCAP in the US. (See links below)
If it is copyrighted, then yes. Created by someone that has not copyrighted their material, then no.
A podcast is provided via the internet and may feature video. Radio broadcasts are (obviously) provided via radio. Radio broadcasts are often available after the initial broadcast as podcasts. Some people refer to any downloadable audio as a podcast.
Not without your permission.
Not without your permission.
Anything new that someone writes can be copyrighted. Technically a work is automatically copyrighted once it is created unless the author explicitly abandons copyright in the work.
Happy birthday is actually a copyrighted song. I don't know who by, but someone must be making heaps!
If someone copies a copyrighted website, then that is piracy and the person could be sued
No you can't, once someone has already written and copyrighted it, you can't
You can't do anything ... Copyrighted media is just that - copyrighted - which means it belongs to someone else and you do not have the rights to reproduce it without their express written permission.
Someone puts it there. Sometimes it's the legal rightsholder (or someone the rightsholder has authorized), but often it isn't.
Blog: a text-based log someone writes and updates, sort of like a web journal. Wiki: a web site anyone can edit, add to, and update, like Wikipedia and WikiAnswers. Podcast: an online audio or video broadcast people can subscribe to or watch on a web site (usually hosted from a blog).
You can find a public broadcast service by looking at different sites. There is a site that specifically has information on this and it is called P.B.S.