If you get rejected your submission date will stay the same as when you first submitted resulting in a lower ranking when you app eventually becomes available. If you do get rejected ask apple to remove the first submission and instead of replacing the binary on the rejected app, submit it as a new application with a newer version number 1.1 etc.
Some people suggest keeping your app free for a week or so during a promotional phase, then raising the price later. I have tried both ways and so far it appears to be 6 one way and 1/2 a dozen the other. For every 1000 free downloads you are getting expect about 10 at $0.99 (again this is my experience)
One minor thing I ran into. Make sure you Small Embedded icon 57x57 matches the Large 512x512 icon. If it is "too" different in their opinion they will reject the app. So avoid trying to showing even a little more detail in the larger icon.
