
Congrats on the Marathon! DH and I will be there too!!
I so know what you mean - I finally decided it was time to take my parents - and my dad is so not into Disney - but he is into Nascar and sports - so I planned our days for maximum appeal. Mom wanted to eat in the castle with DD - done! Dad, not so much - done! I scheduled him to do the Richard Petty Driving Experience! Mom and dad had some park tickets - so they didnt want to buy and go to the parks each day - done - I scheduled Ohana, Wolf Gang Puck's, Cali Grill and just worked around what they would like! (oh, we did have the Free Dining, so that was another plus for dad! lol) When we went to EPCOT dad was parked at ESPN zone - he LOVED that!!
I also made a 3 ring binder filled with pictures of the resort we were staying at, and menus of the places we were going to etc - Mom loved it, dad was happy that mom was happy!

And since I scheduled dad early in the week for his RPDE - it rained - so he ended up going 4 days and got at least one lap in the first 3 days - and the full experience on the last day -
he now LOVES Disney!

It was his best vacation ever!!

Of course for me, it was the most stressfull - I wanted so bad for my parents to love it - that my plans were "perfect" - that dh had to take me back for a trip less stressfull!!

(honestly my mom kept wandering off, and wouldnt answer her phone! Dad would get mad - I'd park him at a CS place and get him a beer and go search for mom - she was always in a store!! lol)
The first time we did the marathon, I did the half but wanted to cheer dh on at MK so went to get on the bus - and I missed the bus - but I met somebody's parents and we shared a cab! So my advice for Marathon weekend would be to hang out at the WISH comp/ forum here on the Dis! or even go to disneyrunning.com for help with the routes and places to watch, busses to catch etc... We had a great time - and dh met up with people while I ran the half - he really had a good time, instead of being alone...
For restaurants what do your parents like? Are they adventurous? I'm sure they'll find something at Boma that they'll love - and just sitting by the pool, or in the rockers watching the animals at AKL will be relaxing...
If they enjoy an adult beverage from time to time - make sure you do the Grey Goose Slush, or the Italy Rosa Regale Champagne... I'd do either Cali Grill or Yachtsman Steakhouse or if they havent done a Tepan Edo style Japanese, they may enjoy that - if they are "down to earth" people watchers Biergarten may be fun - I also wouldnt zone in on a lot of rides, but definately Soarin and Spaceship Earth my parents enjoyed (and of course dad loved Test track LOL) We only did MK one day, (and it was mom's and dd birthdays) - but they were "dusted" the singing quartet sang Happy Birthday - again I tried to do non commando things, CoP, the Blue line in tomorrowland, those relaxing things that they could people watch, HM and Pirates are good rides with fast loading, short lines...
Its so the things that you cant plan - like my parents didnt want to do Wishes - too big of crowds, I did a Fantasmid Dinner Pkg, but my parents didnt stay for Fantasmic - again, it was late, the crowds... so like a PP poster said, you have to think of their needs, likes, and try not to project onto them - in the end, my parents loved it - but I doubt if I could ever repeat some of the unexpected things... (people in line would sing happy birthday, a little girl wanting to pin trade with my mom - and she was happy, but confused "I dont want to give up my pins!! lol They thought she was a CM! You might not want to get them name badges!! LOL)