1) No.
6) DDP is not a good deal for guests.
NOTE: DDP is a huge money maker for Disney. Some people I know say they buy it for the "convenience". If they want THAT kind of convenience, I offer to walk around behind them and pay for their meals with my own credit card and charge them the price of a DDP plan. Although retired, I could then live in the lap of true luxury. Even disBoards analysis of DDP shows it to be a looser for guests.
What a terrible answer. Maybe:
DDP is not a good deal for me... but if answering for someone else w/o understanding what they want to eat, that's awful advice.
You aren't reading my post in the way it was meant in the context of this entire thread/my previous replies. It was a reply to other posts stating the only reason people buy the plan is to save money. Not a brag that we didn't need to save money.

Believe me, I save!
My goodness!

What a topic. I don't care who buys/doesn't buy the dining plan and for what reason, and no one else should either! But some of these posts seem like thinly veiled insults meant for those of us who choose to buy the plan (for whatever reason) and I'm being silly by engaging, which isn't like me.
Eat freely everyone!!!
Yeah, I understand your point. The argument against the DDP is basically that you would spend less... but it's missing the human element. Most people do not buy gift cards and take them with. That's a Dis'er thing to do. A typical guest would show up, see a menu, and order. They would do what they instinctively do, which is apply common sense and not go overboard because they know they will be charging it and going home to a credit card bill.
What the DDP does is helps people to visualize just how much dining will really cost, and pay for it 6 months in advance. When something is paid off in advance, it frees up the pressures on things like not buying a steak every time you go out to eat. Think about it. I don't order a steak every time we go out. Sometimes we'll split an app, because we're not made of money. But on vacation, it's nice to splurge. DDP helps people to do that by disconnecting the payment (6 mo in advance) from the use (when on vacation).
If you don't get this primary benefit, then you shouldn't be discussing the DDP. DDP is not first and foremost a spending engine to reduce costs. It is a way to separate the headaches of life (money) from the aloofness of vacation (enjoying the DDP w/o worry of what you're spending).
Now on a purely financial level, does it save money? Not necessarily. I would say in around half of all cases it's within +/- 10% of what you would otherwise spend. In other words, it's not going to make or break you, so really the intangibles are what matter more.
In the other half of cases, I'd say it comes out greater than a 10% loss 3/4 of the time, and greater than a 10% savings only 1/4 of the time. That's because for it to be a true saver, you have to be in an optimal demographic. WE were in that demographic for a long time! We were 2 adults traveling with 2-4 children and we'd hit up mostly character / entertainment fixed-cost meals. So I'd say if your party has at least as many people in the 3-9 ages (or more) as you have 10 and over, and you're doing at least half of your dining (or more) at fixed-cost (expensive) places, and you tend to eat meat-entrees when given a choice, then the DDP *will* save you money. Now those are 3 conditions and all have to apply for it to be a big saver.
Now that we have more adults, we are not as into the character meals and we get AP/DVC discounts on food, the DDP has become not a good option for us. But it's still a good option for some, and you should really talk to them about their vacation before telling them something is terrible.