Gosh, yeah, sounds like so many severe sensory issues. Serious seeking in the constant chewing (putting things in your mouth gives very fast input, comparatively speaking), walking on toes showing some balance issues (vestibular instability), and a possible vitamin deficiency? She might have some issues absorbing some sort of nutrient, what with all the odd things she tries to eat. Not sure about her intense fear of flies, but I also share that intense fear of being sick, and frankly, since she probably feels out of control to do what she "should" do in a normal situation, I'm sure she feels completely freaked about how she should act in a "special" situation, like being sick. And there are so many different ways someone can be autistic, I just have no clue. But an OT is a fabulous start, and autism specialists would be a great follow-up, like a DAN doctor. I find it really troubling that the pediatrician didn't recommend that to begin with; if he felt out of his depth, he should have called in the big guns. Just my take on it.

Does your daughter like to jump on the bed? If so, you might find a trampoline for her for some good vestibular input. Also, for the chewing, I've heard refrigerator tubing is relatively safe on the teeth and great for input. You may have to buy a lot if she chews that hard, but if she has something safer to chew, it may assist her in avoiding the more dangerous items that she has been using. And I'd get her to carry heavy things any opportunity you can. Have her "help" you carry the clothes basket, the groceries, et cetera. Heavy work like that can often help calm the system, and it sounds like she needs that calming. Even if the root cause is not primarily sensory, this can help with the sensory stuff she does seem to be showing.

Best of luck, and let us know how the eval goes!