Hesselink is a doctor of course, I can't agree 100% with everything he says in that article. Food should be kept to a minimum around Miracle-Mineral-Supplement to get the best effect

It depends on the food how long it will take to digest but I never had any problem
I'd allow 4 hours after a meal for an empty stomach but if a light meal 2 hours should be enough and allow an hour before eating again preferably