Can I travel within the United States with my combo card while AOS is pending?

I am changing the Practice Area so that your question might be answered by Immigration Attorneys.

Yes, you may travel within the United States without restriction.

Yes. An EAD id a federally recognized document that may be used for domestic commercial air travel with a pending AOS case.

Your Advance Parole permission is intended to be used to re-enter the US should you wish (or need) to travel abroad. It does not address traveling to other states within the US. Typically travel within the US is a non-issue for AOS applicants because one does not go through checkpoints, like customs, going from state to state, where you would be asked your immigration status. However, if you are currently out of status while awaiting a decision on your AOS, then one could argue that traveling poses a greater risk to you, regardless of your advance parole permission. See an attorney for more information on this.