How long does it take for superficial acne scars to disappear?

Depends. The deeper the acne infection, the deeper the scar. Cystic acne can scar for life. If it was a deep, bad pimple, theoretically, some scars can take up to a year to heal. Most acne scars will also pigment and that can be permanent. Usually if its superficial, will disappear in 2 weeks.
Depends. Some acne scars fade , some stay forever. Redness will typically fade. Deeper scars will linger and may require intervention to help fade.