Depends. That's a very broad question, as there are many mechanisms involved in the production of different aspects of acne, including oil production. A dermatologist can help you choose a regimen that will work best for your particular situation. As for scarring, the best way to prevent that is to get your acne under control. Again, a dermatologist can help you with that.
Depends. If you have active scarring acne, consult a dermatologist to consider use of Accutane (which is antibacterial-antioil in effect). When no longer having active breakouts, use of mechanical dermabrasion, laser and chemical peels often help reduce the appearance of the scarring.
No they won't. If you've already got scarring from acne, then your disease -- which is chronic, serious, and non-lifestyle-related -- wasn't managed as it should have been. You have my sympathy. If benzoyl peroxide fails, a scientific physician can clear it up in a short time. This is the 21st century. Please get seen. A dermatologist can deal with the scars later.
It can't. The product does not intend to do away scars.
No. Olive oil will lubricate the skin but not improve acne scars.
Treat the acne first. I think the best way to address people with both acne and scarring is to first get the acne under control. There are many options, and I would discuss them with a dermatologist. Many of my patients believe they have scarring, but in reality they have red marks left from previous acne which will go away once the acne is treated. If you have true scarring, other options are available.
Scars. If you control your acne it will minimize the long-term scarring. Basic steps include regular hygiene with a mild soap and water, the use of topical agents like salicylic acid and benzoyl peroxide and the use of non-comedogenic makeup or better yet avoiding make up. If that doesn't work you may need to see a dermatologist about topical antibiotics, oral antibiotics or other oral anti-acne meds.
Different options. Are available... First, you need to get control of the acne itself, if you haven't already. Depending on the size, depth and number of scars you can consider peels, laser treatments, dermabrasion, etc. Seek consultation with a facial plastic surgeon.
Combination. Usually need to combine a few treatments, but if you had to choose one, I would recommend fractionated laser co2 such as active fx.
Scars are permanent. Like all scars, acne scars are permanent. There are things to improve the appearance: laser treatments, excision for ice pick type scars, or fillers are the most common form of treatment. Best to prevent acne.
Acne scars. There are a variety of treatments that vary according to the severity of scars: chemical peels, dermabrasion, laser resurfacing, fillers, fat grafting, excision, grafting, etc.
Serious Rx. I'm sorry your acne got neglected and you ended up with scars. The real scars (not just the brown marks, which fade with time) can be managed by a specialist with a laser, microsurgery or microinjection. Some hollywood stars keep their acne scars for the "tough guy" look.