Are the scars that molluscum contagious leaves behind after the bumps heal able to infect other people?

Probably not, but...: ...you still should wait a few weeks before potentially exposing others, e.g. resuming sex with someone not previously exposed or infected with the molluscum contagiosum virus. The scars themselves probably don't still have virus, but the general skin area might. After 3-4 weeks with no appearance of new MC bumps, you can safely assume you are non-infectious.