Whether obtained via the dining plan or without it, food bought onsite will be higher in cost than food purchased offsite. I can still purchase the same amount or even greater offsite for less than either the DDP cost or the raw OOP cost. Use your own example of three meals a day and compare to onsite costs.
Ok I agree with this statement, that food offsite costs less than the same amount of food bought onsite.
So then. Is this "More for Less" or "Less for Less"? If 3 people could spend $75 at Yak & Yeti, and then ride EE and Kali, or, in the same amount of time, drive out to a Chilis, eat the same food I could get at Chilis by my house, and miss out on 2 rides... but... do it for $60... We've saved $15. So did you get the same experience, or more, or less by doing so? Then, factor in the gas money for peddling around parking lots and I-Drive. I know you say it's cheap, but even 25 miles of misc tooling to get into and out of parking lots can add up to $5 pretty quick. Now your savings is down to $10.
Then you could say "yeah but eating at Chilis doesn't cost us $60 cuz we split a fajitas and don't order drinks". But then you have to factor that at Y&Y, it wouldn't cost you $75 to split an entrée and not buy drinks, either.
Now you've shown a pretty good touring plan that gets one on the rides you want... but it came at a steep price, of buying Uni tickets and Cape Canaveral tickets in addition to Disney tickets. Given I don't like just how much time you are in the car... this seems like more driving than I do in a week of going to work... but if you or anyone doesn't mind the driving, then the strategy is viable. All you have to do is show your actual costs make it all worth it.
OTOH, if you WANT to take in Cape, and you are willing to pay for it, fine. e.g. we do LEGOLAND. I don't do it cuz it saves me money over spending the same time at Disney, on the contrary it costs quite a bit more, but it's what we want to do so we do it.