During the second world war, did the French Resistance kill civilian or paramilitary targets? And if so, how often did this happen? Additionally, were there any murders of collaborators after the war?
Unless otherwise noted, the quotes below are from "Ousby, Ian Occupation The Ordeal of France, 1940–1944, New York: Cooper Square Press, 2000 and were found by consulting the Wikipedia page on the French Resistance.
Aside: OP included paramilitary targets in the question. That would make the answer to the question a simple link to the Wikipedia page, which goes into chilling detail on the war between the Maquis and the Milice. I chose to search for examples of attacks on civilian targets.
By January 1944, a civil war had broken out with the Milice and maquis assassinating alternatively leaders of the Third Republic or collaborators that was to become increasingly savage as 1944 went on
1944 had simply become the time for settling scores, any scores, for revenging grudges, any grudges. Agreed on this common imperative, the sides in the conflict blur and become almost indistinguishable from each other. The Milice hit squads pretended to be the Maquis; the Maquis hit squads pretended to be the Milice. Sometimes it was impossible to tell which was really which, and sometimes it hardly mattered.
In the town of Voiron, close to Grenoble, in April 1944, a Maquis assassination squad entered the home of the local Milice chief and killed him, his wife, his infant daughter, his 10-year-old son, and his 82-year-old mother.
Outside the village of Saint-Laurent in the Haute-Savoie, a mass grave was discovered in May 1944 of eight gendarmes known for their loyalty to Vichy kidnapped by the Maquis from Bonneville who had been lined up and shot by their captors.
By this time, the maquis had formed assassination squads to kill collaborators and on 28 June 1944, a group of maquisards disguised as miliciens were able to enter the apartment of the radio newscaster Philippe Henriot who was serving as Minister of Information and Propaganda in the Vichy government and shot him down in front of his wife.
Besides for attempting to establish a government, the Resistance took its revenge on collaborators who were often beaten or killed in extrajudicial executions.
Crowdy, Terry French Resistance Fighter France's Secret Army, London: Opsrey 2007 page 58.
Immediately following the liberation, France was swept by a wave of executions, public humiliations, assaults and detentions of suspected collaborators, known as the épuration sauvage (savage purge). Jackson (2003), p. 577
In short the French were human, and demonstrated the normal human desires for vengeance.
The French Resistance (and other resistances) killed civilians who were viewed as "collaborators." They were out to weaken the civil structure of German rule, as well as military targets.
"Resistance" brought about bitter civil wars in German-occupied countries between pro- and anti- German groups that hated each other even more than they were against (or for) the Germans. This was particularly true in the former Yugoslavia, but true enough in France.
After the war, collaborators were (mostly) tried and executed if found guilty, rather than "murdered," since the Resistance then had the law on their side.