1 hv no idea
You'd need permission from the maker of the sign, to make a derivative piece using it. Being 'foreign' doesn't matter, most countries are signatories to the Berne Convention and acknowledge copyrights from each other.
The author of a creative design is the owner of the copyright automatically.
Copyright someone elses design
If the design meets the minimum requirements for copyright protection, yes.
Aspects of the design that are entirely your original work, such as a piped or carved design, may be protected by copyright as a work of visual art; the US Copyright Office has asserted that permanence is not required for protection.
Yes, if the web design legally belongs to you. Add © copyright YEAR NAME OF COPYRIGHT HOLDER to the bottom of each page of the website. This will signal to honest people that the web design is copyrighted and may not be used elsewhere.
If you control the copyright, anywhere. If you don't control the copyright, and don't have a license, nowhere.
Architectural works are protected by copyright.
Ideas cannot be protected by copyright, only the expression of the ideas.
Roger T. Hughes has written: 'Hughes on trade marks' -- subject(s): Trademarks 'Hughes on copyright and industrial design' -- subject(s): Copyright, Design protection, Design, industrial, Design,Industrial
Absolutely. It's automatic once the design is fixed in a tangible medium.
The Australian Copyright Council website has an excellent page devoted to graphic design issues; see the link below.