I will answer your last question.
After I changed my diet, I was very strict the first few months no sugar at all, no dairy and low GI meals. Sleep cycle and stress are very important for me. I started going to bed at 10 and waking up at around 6 am. I would say I had 80-90% improvement in the first 3 months. PLus my digestion improved alot. My acne was very managable and I did not feel like I cant see people without make up. No cystic acne as soon as I discovered my intolerances towards citrus and eggs. I still breakout once in a while if I cheat (conventional dairy- while eating out-being indian a lot of food cooked in my friends and family's homes is made in ghee/butter/yogurt or desserts).
There are times when I am absolutely clear for 2-3 weeks and breakout a little around my period. May be 1 or 2 acne, but it is so much better. I also wax facial hair, as I am brown skinned with dark hair which is visible, and may get few tiny bumps a few days after waxing. I had acne which was bad enough, that the only derm I saw in the US prescribed me antibiotics and told me if there is no improvement in the next 2 months he would start me on accutane.
It has been around 15 months since I started the holistic path and other than acne I feel this lifestyle has helped me be more energetic and efficient at work, home and people say I look much happier. I still make baby steps towards improving my life daily, like doing yoga, (started in the last few months) and try to eat healthier, by beeing innovative with new recipes. I would say I am clear 95% of the times. The last stretch seems a little difficult but I am learning to deal and not fret about it. Like alternativista told me only we are so critical about our own acne. Noone else notices it as much.
I love bananas and though I dont eat them alone, they are amazing in green smoothies(low GI). And I may add a small potato to a vegetable soup, but make sure you are eating a salad or lots of veggies with it. Give those a shot.