loveless / unloved, or lonely
unexpectedly
That is Narcissism.
The likely word is unfailing.
Aloof
The word is cohabitation.
There is no one-word substitute in English for "son-in-law."
The word you want is florist.
The adverb could be freely or voluntarily.
Sportsmanship is a word substitute for spirit of game
The word metalworking is one word.
There is no associated "philia" for cars (autophilia is self-love). They are usually called car collectors or car buffs.
eat, use