My DD is without a doubt on the spectrum, and she has a sense of humor. It's atypical for kids on the spectrum to have a sense of humor, but it isn't a litmus test.
Going back to your thread title -- how to sort out what is a quirk from what *might* be ASD -- it isn't your job to do that. And no body on this thread is qualified to do that. This is a job for a specialist with years of education and training, who then spends hours and hours with your child. This isn't a dx that comes from a checklist.
Your child has multiple flags -- plenty to warrant a full evaluation. And that's all ANY parent needs to figure out on their own.
Whatever is going on with your DD, getting professionals involved *may* help your whole family. Understanding what a kid needs and then being able to tweak life around to provide it makes family life a lot more sane.