I think you are exactly right. Of course, if you are not trying to get one over on Disney and a CM questions you, you aren't going to get angry and defensive- you are going to be confused and apologetic. If you are being deliberately deceptive, you are more likely get nasty w/ the CM.
My advice, the DDP is super easy to use when you get going on it. Don't worry about tally marks and spread sheets. It's too much to worry about when you are on vacation.
DO bring along your confirmation numbers and ADR/times.
DO save your receipts and verify (I just eyeballed it) that you are on track w/ your DDP credits at the end of each day. Unless you are splitting up every single day at every single meal, it'll be easy to do.
Snack credits can get away from you, but they are the least "valuable" aspect of the plan anyway. We ended up with way more than we thought at the end of the week.
Don't deliberately order more adult meals than you are entitled to.
Don't make yourself crazy keeping track of how many kid's meals you've ordered.
Don't go out of your way to find a CS location without a kid's menu- that just seems like a waste of valuable touring time. (I read someone post that they were going to Disney MGM studios EVERYDAY for their CS meal.... wow!)
Do have fun! And have a dessert that you wouldn't normally have ordered for me!