no.
See the related link for the symbol.
no
No.
Scroll down to related links and look at "Loudspeaker symbol and google images".
See related link.
Math
No, it was actually a Hindu symbol for strength and unity prior to WWII
I think you are referring to the Unitarian Universalist symbol. See the related link.
The recycling sign or symbol has three arrows that form a circle. I have included a related link which is an image of this symbol.
It's called the Ampersand. See the related link for more information.
It represented a symbol of darkness, which is greatly related to Hades, being the god of the underworld and its inhabitants.