"But I'll settle for my little corner of the world. My neighborhood (or town, at most)
“It's just hard to see under all that stomach” Refers to the expression “to throw one’s back out” which means to have a disk slip or strain a muscle in your back.
To throw out also means, “to dispose of.”
Dennis thought that Mrs. Wilson meant that her husband threw out (disposed of) his back. That’s why he said “No, he didn’t. It’s just hard to see under all that stomach (it’s still there, Mrs. Wilson, but it's just hidden because he is fat).”