Thank you for your last reply.
1) From your previous posts, you seem to suggest that CP and I485 go thru the same NC process. Then what is the advantage of CP? Once NC is cleared, I485 should not take long either, right?
2) I filed I485 already. If I switch to CP after I get AP, will my AP be still valid?
3) You said that I cannot come back based on 30 days no visa rule if my CP interview fails. Is it because I apply for a visa and 30 days rule only applies if no visa interview outside US?
4) Can I make a H1B visa interview appointment at the same time with the CP interview? So if my CP fails, I can get a H1B visa to come back to US.
5) If Yes to 4), then how long will the H1B background check take? Can I get the visa in two days so that I can come back to US to continue my job?
6) How long does CP take in Canada now?
Thank you VERY MUCH for your help. Sorry that it is a little bit long.