I've experimented with more frequent pulses or larger ones. To be honest didn't notice a difference. I liked the more frequent pulses only because I make MAG-10 slurpies out of my MAG-10 and it felts good to have more of them! But honestly the original schedule will work.
Minor differences, many a bit more carbs, which ain't bad since it will give you a more stable glycemia and it's a type of carbs that actually help with fat mobilization. I wouldn't change the original plan.
Same rule applies. I'd try to keep it as clean as possible, but it wont kill your progress if you have something "less than ideal" once in a while. Don't gorge yourself though. You should feel full and satisfied but not stuffed/uncomfortable.