Hi,
I'm a physical therapist who specializes in children. 9 months is still not considered abnormal for a child to crawl. Children crawl at a wide range of ages. It is important that she is wanting to move, which you say she is, by scooting on her bottom. She may just be a little slow to crawl, or there could be some physical reasons making it hard for her to learn.
Shorter, heavier babies tend to move a little slower than long, lean ones. Some babies are also really sensitive on their hands, which can make it hard for her to put her hands on the floor to crawl. You can try to play with different textures to help her with this if you think it could be the reason. Some examples would be rubbing her hands (gently but firmly) with rough towels and soft cotton balls, and letting her play with her hands in sand. It is not absolutely necessary that she crawl, but it really does help strengthen the rest of her upper body muscles, which can help her physical development later. I would highly encourage her to play on her stomach. One good activity to do with her is climbing up and down stairs on her stomach...always with your help for safety!!!
If you are really concerned, or if you notice other areas where she might be developing slowly, you are entitled to a free development assessment from your local birth to age 3 program. You can usually find it through the Health Department. Some totally "normal" kids sometimes get a little stuck in their physical development and a specialy trained pediatric PT can show you a trick or two to help get them going again. (One word of caution though, your average PT who works with adults may not be as helpful). Unfortunately, most pediatricians never think of using a PT unless there is something major wrong.
I would check with the doctor about the feeding issues. She may need some medicine or it could be a food allergy. I wouldn't eat either if it was making me sick!
On the sleep issues, I have discovered, thanks to my 2 year-old, that they will go through so many sleep changes. I can't count how many "stages" he has gone through by waking up many times at night. I'm looking forward to the time when he's done with that! Good luck.