Антонимом a troublemaker

appeaser peacemaker arbitrator conciliator pacifier peace-maker mediator adjudicator umpire intermediary judge arbiter referee middleman interceder negotiator broker intercessor go-between moderator reconciler intervenor honest broker pacifist peacemonger linesman peace-monger umpie peace-lover satyagrahi peacenik dove conscientious objector liaison officer assistant referee line judge passive resister moderate placater pacificator interposer agitatee

sweetheart darling angel dear sweetie dearie gem cherub sweetie pie god

goody-goody

angel paragon humanitarian good person kind person paragon of virtue one in a million

advantage aid assistance behaviour behavior benefit blessing favor favour good goodness happiness help kindness manners obedience right virtue

employee follower worker

patriot

optimist

law police

friend

at sea at second hand at short notice at sixes and sevens at some point at some point in the future atrophying atrophy atrophies atrophied atrophic at root