1. in order for everyone to get the 20% off from the DDE we will all need to be on the same receipt correct.....
That is correct.
2. If we are all on the same bill the 18% will be automatically added... what if we have horrible service... shouldn't that 18% be able to be changed?????
The same if we have great service I realize we can add more..... Do I have the opportunity to leave less than 18% if the service is really bad???
Talk to a manager, they can modify the tip. This is the same for parties of over 6 or with DDE
3. What if I just use my DDE card for myself and have only my meals on my own bill... will the 18% still be added as there will be 6 people at the table....
Yes, 18% is added for DDE, regardless of party size.
4. Can the server ring up separate bills (for the 6 people it would be 4 separate bills)? Can they still use the DDE for the 20% off if we do separate bills? And if we do have separate bills will the 18% be added?
They can do seperate bills, but you cannot get the DDE on the seperate checks, unless they have their own DDE card. And as was already mentioned, you are still a party of 6 or more, so 18% will be added to all the bills.