The standard phrase is neuf et d'occasion, but neuf needs to agree in gender & number with your noun ... for example "new & used merchandise" would be translated as articles neufs et d'occasion.
No, bikini is not a French word. Although it was used in French.
This word is used to describe the French baguette.
Since the @ symbol is not actually a word, but a symbol used to denote a word, there is no French translation of it. The French word for "at" is "a" but in French, if one is writing an e-mail address, @ would still be used.
nouveau
new - nouveau, nouvelle
nouveau
The same word is used in French, but spelled with a hyphen: arrow-root. It is masculine.
New Caledonia was colonized by the French or used for testing by the French, I think.
nouveau, nouvelle
New
yes. aeropostale was established in France therefore they used a French word.
The word 'bacon' is used in French, but more usually it would be 'lard'.