Welcome to my family too!
My hubby is a plain meat & potatoes guy (no sauces, etc..) along with picky kids. I was really nervous since all the good steak places seemed to add sauce. I had read I could order without the sauce and I was able to do so just fine everywhere (I'm a plain food person too but not quite as bad as DH - I forgot the first night to order my steak without sauce and well it had a zing to it that I didn't particularly care for so I remembered from then on! LOL!). My 5 year old literally ate Mac & Cheese *every* day for Lunch & Dinner (it got to be a running joke - since he likes other stuff but for some odd reason he got on a Mac & Cheese kick there).
We stayed at the Contemporary and we were on the Premium plan so it affected our choses of places to eat.
We ate at the
Yachtsman Steakhouse
Concourse Steakhouse (we had 3 meals here just mostly because of where we stayed)
Liberty Tree Tavern
Fulton's (I really liked this place - it was comical though that NONE of us like seafood but were eating here).
Rainforest Cafe
Chef Mickey's
Tony's (this wasn't on my original list since I didn't really think DH would like it but we ended up there and I liked it).
Sci-Fi
Trail's End (that one wasn't so great but it was at lunchtime and not really a whole lot there DH liked).
Breakfast (I know you said you will be eating mostly at the conceirge lounge)
Crystal Palace
CRT
Princess Storybook in Norway
Donald's Breakfast
I hope that helps. I did try to stick to buffets or your more basic fare restaraunts. They were fine with asking for no sauces and just a plain old steak & potato everywhere.