It’s most commonly used to refer to the USA.
Most people use “Amerika” for “the USA”. If one talks about “the Americas” we use “Südamerika” (south) and “Nordamerika” (north).
Stupid question is that how they would spell America in Germany “Amerika”?
Something a person that definitely doesn’t speak german would say. We spell it exactly like this.
It’s obviously pronounced Kicago, just like Chamäleon, Chemie and China :)
Depends on the context. If it is written/talked about in a geographic context, it will usually mean “the Americas”. If it’s in a political context, it will mean “the USA”.
Keep on mind that reputable news outlets won’t use “Amerika” when referring to the US however, they will use “Vereinigte Staaten” (United States). “Amerika” as a term for the US is very much a colloquial thing.