"nice guys finish last" Actually, "kind, emotionally sensitive, and caring about others—holds great appeal" --from linked article
“whenever you find yourself on the side of the majority, you should stop and reflect” Attributed to Mark Twain
"So live your life that the fear of death can never enter your heart" Attributed to Tecumesh, Native American Shawnee leader (1768-1813)
“The pen is mightier than the sword” The exact phrasing dates to 1839, but "the idea of communication surpassing violence in efficacy had numerous predecessors" --Wikipedia
"money doesn’t grow on trees" said to warn someone to be careful how much money they spend, because there is only a limited amount --dictionary.cambridge.org
"use it or lose it" if you don't continue to practice or use an ability, you might lose that ability --Collins Dictionary
"good things come in threes" if a fortunate event has already occurred twice, a third fortunate event is likely to occur --request