From the information that you provided, you should be okay.
Mr. Shusterman's (former INS Trial Attorney, 1976-82) response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Shusterman's statement above does not create an attorney/client relationship.
A. Impossible to tell without first analyzing your employer"s entire H1B petition.
2.. If CIS approves the new employer's petition, and does not find any issues relating to possible fraud, etc. then in all likelihood yes.
Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
Without knowing more about the petitioner, it will be mere speculation. If you already have a valid visa (from your travel to U.S. Consulate in Canada), you will not need a new visa to travel back to the U.S.
This response is general in nature and cannot be construed as legal advice, given that not enough facts are known. Any comments offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship. You are encouraged to seek independent and private counseling for a complete review of your case.