If 5 people are going to eat at a place, can you have two people use their own DP, the other 2 people use their own DP (different party) and then pay OOP for a child that is dining with you not on either parties plan?
In other words, on the DP, can you have separate checks - and have different methods of payments?
You can absolutely split the check any way you wish. In fact, paying OOP kids' meals at menu-service (yes, it's my new phrase

) restaurants is a relatively typical method of conserving credits and spending less if you've gone over (kids' menu meals are cheaper than buffet meals, and usually opposite for adults, especially when doing the buffet at breakfast).
As far as I know yes no problem. I know for sure you can POP for the childs' meal-even if the child is on the dining plan-so it should be no different if the child in not on the plan. Actually the hard part would be having a child staying with you (or anyone for that matter) that isn't on the dining plan if you are. Everyone in the room has to have the same plan.
Now if your party is over 6 and trying to avoid the gratuity being added-I thin you'd be out of luck. I think even with separate checks they still count the table as being a party of 6.
Yup, the number is 6 and they don't care if you split the check 7 ways. If there's 6 in your party, you "qualify" for the party of 6 "rule".
As far as the child not on a plan, there could be several valid reasons. The child isn't staying with them or the child is under 3... or... um. Ok, 2 valid reasons

. Oh wait, 3, if you add the child when you get to the resort, they won't have to be on the package (of course, they couldn't ride on ME either... but that is neither here nor there

). (Yes, I could backspace and make it sound like I got it right the first time, but what fun is that?)