Various portions of it (the music, the French lyrics, and the English lyrics) are owned by Polygram, Universal, and WB Music. Most administration for the song itself can be handled through Hal Leonard.
Certain performances and recordings will have their own protections.
The photographer owns the copyright of any photograph unless there is a written and signed agreement with a client that states otherwise. If the photographer is an employee of someone else and being paid for his employment, then the employer is legally the "author" and owns the copyright, under US law. It is quite possible, and often the case, that a person may own the only copy of a photograph but someone else owns the entire copyright but no copies.
Nobody owns the copyright of a single word. Perhaps you mean trademark.
Assuming the works are still under copyright or trademark protection (and haven't fallen into public domain) they would be controlled by whoever acquired the intellectual property of the respective breweries when they ceased operation.
the coca cola company owns the copyright
A minor owns the copyright on any works they create.
Universal.
No, there are unofficial parodies but no official rewrites since she still owns all the copyright and therefore there cannot be a rewrite until her copyright expires.
If it was formally filed and probably was the US copyright site has a search function to show who owns the work. If not filed creator owns for 75 years.
Word Music.
Rankin/Bass.
Rondor Music.
Paramount.