Unfortunately, I don't believe that taking collagen supplements would help with acne scars. Collagen is a protein which will be digested in your stomach and will not end up in the skin. Taking oral Vitamin C (or eating fruits and vegetables which is preferred) and applying a good Vitamin C product to the skin might be helpful to promote collagen synthesis, since Vitamin C is required to produce collagen.
Absolutely. Good nutrition, oral vitamin C, and collagen stimulating creams such as RR Retinoid Repair can enhance results from acne scar treatments.
Scars are much more difficult to treat. They need lasers, Infini, PRP, subcision, TCA Cross, microneedles, or Bellafill to improve. See link please.
Collagen supplements won't help heal your acne scars. Topical therapy, injections, lasers, and micro needling, all help with the acne scars. Be sure to consult an expert. Best, Dr. Green