"Middlemarch" might be one of those books, like "War and Peace," that's actually better to read when you have a few miles on your odometer. Many of its subtleties might sail over the heads of 13-year-olds who typically respond better to the blunt-force messages of novels like "To Kill a Mockingbird."
You are so right about the epigrams. I'm glad you don't hold it against Eliot that she gets off some zingers about your sex (one of which begins--I think I have this right--"men's minds--what there were of them" ...). A passage at the end of the novel, which sums up one of its themes, might be my favorite line in all of literature apart from Shakespeare: "The growing good of the world is partly dependent on unhistoric acts; and that things are not so ill with you and me as they might have been, is half owing to the number who lived faithfully a hidden life.”