Hi Cheryl!
Generally speaking, it is impossible to see and do everything in Walt Disney World, even if you were staying two weeks. I have been to Walt Disney World many times in my life and I still have not done everything. However, I think your plan is fine. I think most guests can definitely experience the majority of the attractions in Hollywood Studios and Animal Kingdom by spending one day at each park. In fact, many guests will say Animal Kingdom is only a half day park, though I personally disagree and can easily spend a whole day there.
The other two parks are more difficult to estimate. Epcot is a very large park to walk around. You could easily spend most of a day just in the Future World portion of the park. If your family wants to spend a lot of time in World Showcase, then I would suggest considering spending 1 and a half to 2 days in Epcot. Likewise, families with young children could easily spend 2 days in the Magic Kingdom. Families with older children might only spend 1 to 1 and a half days in the park.
Using my family as an example, my 5 year old loves the Magic Kingdom, followed by Disney's Hollywood Studios, Epcot, and then Animal Kingdom. However, my 10 year old loves Animal Kingdom, Epcot, the Studios, and then the Magic Kingdom. My favorite is the Magic Kingdom (and I could spend multiple days there), Epcot, the Studios, and Animal Kingdom; sometimes I flip flop between Epcot and the Studios. My wife loves Epcot.
With regards to the Disney Dining Plan, some guests save a lot of money, some save a little, and some actually spend more when on the
Dining Plan. I suggest looking at the menu for various Table Service and Quick Service restaurants at the independent website AllEars.Net. They do a great job keeping their menus up to date.
Enjoy planning and write back if you have any questions!