I don't remember the exact date that I submitted my application. It was sometime late April to mid-May if I remember correctly. The sooner you submit the better! After you submit, then you have to send all the copies of your certificates, GRE score, etc. They'll email you with the email address to send them into them. I was interviewed and accepted pending the chem class. So, yes, you can submit without everything. And, yes, they may choose to interview you without everything already submitted. I've heard from others that they were accepted pending PALS, GRE scores, etc. If you haven't completed something yet, you might want to work it into your statement that you're working on it.
The pre-anesthesia class worked great for me. I had already taken organic chemistry, so it was an easy review. It's expensive, but I didn't lose time at work because of it. With the local alternatives, I would have cut down on my hours working and thus would probably have spent as much if not more money. It's also great because I got to experience their software package. It made it an easy adjustment to classes this semester.
As for GRE scores, I think they want a score of 155 on the quant section. I believe there are a few who got in with a lower score but they had other strong points.