What I love about these movies is they're a chapter in a story. Two orphans had a great adventure and it ends with them saying goodbye and flying off into a sunset. A little boy pledges his love to a fish and it ends with a freeze frame. A young man and woman part ways after falling in love saying they'll meet again. I think the epilogue in Porco Rosso illustrates it the best. I love that.
Yes, but the interesting parts of nausicaa only happened in the later part of the story. The real interesting moral issues / philosophical ones happened in the last two books.