In the US it is not as long as it isn't used for fraud. For example, you're allowed to make a flat penny as a souvenir, but you couldn't take a penny and shave it down and use it in a vending machine as a dime.
yes
Depends where you are. In most countries, it is totally illegal to deface currency. In others, it is illegal to deface them up to the point where they can no longer be used as currency.
In most countries, it is illegal to deface, disfigure, modify, mangle or mutilate the currency of that country.
Most countries have a policy making it illegal to deface the currency of that country. I would suggest that if you intend to make a timepiece for personal use and not to make a business out of it, you should be safe.
Yes, it is illegal (as stated by the Currency Act and the Canadian Criminal Code). See 'related links' for more information.
Yes. It is illegal to deface it, because it is considered government property.
It is illegal to deface public property in the state of New Jersey.
It is illegal to shred, tear, or mar or otherwise deface any US currency. This includes melting coins. An exception is made for penny smashers. In addition, no one would probably be too bent out of shape if you melt one penny or one nickel. But the destruction of US currency is a federal crime.
Only if it belongs to someone else.
In most countries it is illegal to deliberately damage, deface or destroy money.
None. It is illegal to deliberately damage, deface or otherwise mutilate Australian coins.
Yes, deface is a verb.