Whether to get the dining plan or not really depends on who you ask. We got the basic plan (1ts, 1 qs, 1 snack/day), since we did a few double credit meals we did have to pay fro a few meals out of pocket but for the most part we enjoyed not having to worry about what we were ordering and knowing it was already paid for. The deluxe would definitely be way too much food for us. I priced it out before we left because upgrading would have only been another $500 and I was figuring $200-300 out of pocket for meals not included on the dining plan (I like to overbudget that way if we spend less I'm happy

) In order to use all those table credits I would have felt like we were always eating and sometimes it's just nice to go to a quick service rather than have to have a reservation (and don't forget you need to tip at every table service meal, so that is an additional cost, I believe it was 18% included in the bill but not covered by the dining plan). Ultimately the basic plan worked well for us, we used our snack credit to grab a quick muffin or cinnamon roll for breakfast (and I brought granola bars with in case anyone was hungry beyond that, kids are surprisingly easy to fill up when they have other things they are excited about seeing/doing

and the quick/table service for lunch/dinner mostly. You can find menus for everywhere online. I really planned our meals, even our QS meals I planned where we would eat (I usually gave us two options depending on which park and what area of that park I felt we'd be in at meal time), you can price out what you feel everyone will eat and decide from there if you feel the dining plan is worth it for *you*.
I really feel like everyone should plan some down time where they can do whatever...don't overplan yourselves to the point where you see something you think you would enjoy but can't do it because of other obligations. There's lots to see, Disney World is definitely a place for those who enjoy attention to detail. Your boys will likely enjoy some of the little things. Sorcerer's of Magic Kingdom on Main Street, the cell phone game in Epcot (can't remember the name at the moment, they give them a cell phone and a 'mission'). There's a Chip and Dale campfire, free of charge, at Camp Wilderness, they have pony rides and archery lessons there as well. I guess what I would recommend would be based on what your family enjoys. We didn't do any of the parades, we just aren't parade people...and for Wishes my favorite part was the castle projection show before the fireworks started. My favorite fireworks show was definitely IllumiNations in Epcot. We really enjoyed Epcot much more than we anticipated in general. As long as you are in the US it might be worth seeing some things in Florida that aren't Disney.
Legoland or something.
If you are around the first Tuesday of the month, at 5pm the
Lego store in downtown Disney does a free build, kids can build a figurine and bring it home for free.
There really is so much you can do to make it special but at the same time, it will likely be the trip of a lifetime even if you don't do anything 'extra'