The following is what I get from a conversation with an immigration attorney sometime ago.2006gc said:ixora78,
If you have an AP, then there is very little or no risk at all even if I-485 is denied. If I-485 is denied, your spouse can still enter this country using H-4 visa. Only when she uses her EAD, her H-4 gets invalidated and you need to reapply for her nonimmigrant status (I-539) if her I-485 is denied. She will still maintain her H-4 status if she uses the AP (I-131 document) alone.
Check with an attorney if the above statements are true.
Your GC will not be affected even if her I-485 is denied. But your I-485 denial may have an impact on her case as she is deriving her benefits as your dependent.
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If you use the AP to enter the US, your status become that of an advance parolee. Your status is no longer that of H1B. You cannot use your H1B to work. You need to use EAD to work.
If you enter the US with H1B visa, you keep your H1B status. You can use either H1B or EAD to work.
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A similar logic will apply to the H-4 dependent, I guess. In my opinion, using H1 or H4 will be safe if your I-485 is pending.