Thank you for your query at DoctorSpring.com
If root canal really necessary the procedure should be carried out by an endodontic specialist (root canal specialist).
Any root canal if properly done can neber cause pain.
Having said that, if associated tooth gets infected in future (sometimes in chronic long standing cases or in teeth with history if physical trauma, diabetes etc) sometimes the root canal treated tooth can still cause pain because of infection in surrounding bone, tissues.
Putting a crown or not is not related to pain.. as such it prevents tooth fracture in long run.