2. What would an advanced civilization desire or require from the equivalent of rats, if we're lucky?
It's like dating in high school. The troglodyte rarely scores the Prom Queen. Nothing in common.
The difference is, that the troglodyte and prom queen pass each other all the time in the halls, and, given the intelligence of most prom queens probably have a lot of classes in common.
In your analogy, the trogs are sitting in their little enclave in the cafeteria. Somebody mentions the prom queens in movies and asserts that the odds are millions to one that they must exist. The Fermi troglodyte replies: "how come there aren't any in our school?"