Though it is almost never used for a person, it would be a hydrophile.
A bibliophile loves books
There is no associated "philia" for cars (autophilia is self-love). They are usually called car collectors or car buffs.
amphibious
There is no one-word substitute in English for "son-in-law."
The word you want is florist.
Aquarium
Sportsmanship is a word substitute for spirit of game
loves is one syllable
The word metalworking is one word.
eat, use
The word that works is idiot.
what word can I substitute for constitutes