It is called a house call (sometimes erroneously used as one word).
There is no one-word substitute in English for "son-in-law."
The word you want is florist.
Sportsmanship is a word substitute for spirit of game
"Squirrels" has two syllables. It is frequently pronounced with one, but it has two.
The word metalworking is one word.
One possible substitute for "their" is "his" or "her" depending on the gender of the person/people being referred to. Another substitute can be "its" when referring to a non-human object or entity.
eat, use
The word that works is idiot.
Elevate
A walker is a pedestrian.
Traditionalist