I read a book on long journeys to avoid boredom
No, "journeys" is not capitalized unless it is at the beginning of a sentence or part of a title.
The mafia extorted money from local businesses by threatening them with violence.
No
The correct phrase would be "on your journeys" when talking about being on a trip or traveling. For example: You have taken many photos on your journeys. However, you can say "at your journey's end". For example: Be sure to take many photos so you can share them at your journey's end.
The plural of journey is journeys
a donkey, and a moose
That depends on your driving style and the type of journeys you do. Harsh clutch use on short stop/start journeys will knock a clutch out much sooner than smooth use on mainly long motorway trips.
no, you only use apostrophes to show ownership, or to replace letters in shortened words.
Dangerous Journeys happened in 1992.
Mysterious Journeys was created in 2002.
Mysterious Journeys ended in 2007.