Glad you enjoyed it and even if you end here, that's still great. Having read your bolded points, I'd still recommend you continue. It IS a single longer playthrough - you've only played half the game. Routes B and C introduce new combat mechanics, new characters, and is where the story actually gets good. Route C is 100% new content the whole way through, and is where the story really gets interesting.
People make a big deal of route B because it's mostly the same content from a different perspective (there are a couple sequences that are different, and there are some new short cutscenes interspersed), and people are divided on the new combat mechanics. But it's the shortest part of the game though, you can skip the sidequests and power through in half the time or less to reach