http://www.immigrationlinks.com/news/news301.htm

See item 3.
I understand that if you use AP to enter USA, you are in AOS status.
However, this memo says even though you are AOS, if you had H1 status before, and you have valid and approved H1 petition, you can go back to H1 status.
Usually, when you extend or transfer your H1, you get a new I94, you automatically go back to H1 status.
However, someone says you may get a H1 approval without I94, then you have to get a H1 visa to go back to H1 status.

Item 4.
You can continue to work with H1 approval after using AP.