Using AP after visa rejection

[parthan]

I am currently in US. I have Advance Parole document with me. But I need to get my H1 stamped, next time I visit my home country, because I need to get an H4 for my spouse.

My questions are

1. If my visa got rejected can I use the AP document to get back to US?

2. If I can get back to US using AP and start using my EAD can I again appear for H1B stamping interview?

3. If they reject my visa with 221g(blue) at my home country, and I got back to US with AP, can I appear for H1B stamping interview at Mexico or Canada?

Any reply greatly appreciated, thank you for your time.

Thanks,
SKP