Sorry you don't like fanny packs. They are much better than a murse. Look at decent Mountain Smith or REI one. Perhaps you have just used cheap ones in the past.

Also, the bus do NOT make your car unnecessary!! Often, you can get somewhere waaaay before the buses run and beat the crowd by an extra 30-60 minutes, esp the water parks.

Parkhopping will eat more time than you realize


Good shoes
Good hat

Fanny packs for you and wife with the following:
camera
sunscreen
rain poncho for everyone. Carry a 99cent one on nice days, and a "good" Walmart one on rainy days. The cheap ones can be used as seat covers on wet rides so your butt isnt wet the rest of the day.
small windbreaker-good if your wife gets cold easily. hot and sweaty or wet from parks, then inside real cold a/c for dinner, a light packable jacked takets the chill off.
very small FAK with tums,motrin, bandaids and blister stuff
SAK
small light such as Photon or Fenix AA or AAA light
gum
chapstick
purell hand sanitizer
cell phone or FRS radio so you and wife can split up and rejoin if needed.
individual crystal light to make water fountain water taste ok
park map

copy of unofficial guide but leave in room- to heavy to edc at WDW

Plan your day and start early!!! You will get more done by 10AM than you would believe. Most folks want to sleep late and show up at 10 and then the lines really start.
Avoid the park that opens 'early'-thats where all the newbies go!
WDW is not a golly gee whiz vacation. It requires planning or else you will spend most of your day wandering, riding a bus, and standing in line.
Going back to the room for a nap via the bus will eat 1.5 to 2 hours of your day and is really only feasible if you are staying at the polynesian, comtemporary or grand floridian.
Take one day and go to one of the water parks. they are great. Blizzard beach for your kids ages IMO
dont ride the bus to the water park,drive. be there before they open and you will have 1/2 hour or more before all teh bus riding guests can get there and go thru the turnstiles and get settled. do the big cool slides first!
Park hopping eats 1-2 hours as well. Dont spend too much time of your vacation on a bus.

Our typical day was at the park before opening, get in and do the big popular stuff right off the bat.
About 3 when crowds are at the biggest and it seems the hottest, hop to EPCOT and we would eat dinner at a sitdown restuarant (make reservations NOW and plan your days as best you can) See EPCOT before and after dinner or go back early and enjoy hotel pool.