H-1 to TN Question

[looking4rental2015 0]

Hi All, I am Canadian citizen and currently on TN visa. One of new job is offering me H-1 and later greencard. I have below list of question in the worst case scenario. If I need to come back to Canada in future and want to work on TN again. I had experience with H-1 in 2008 and left USA because of job loss.

 

Questions:-

1.       If Greencard (I-140) is filed and something goes wrong (layoff) and need to come back to Canada in future after 2-3 years and I want to try for TN again than Will it be possible to get TN again?  

2.       If question # 1 Answer is no then will it be possible to revoke greencard (I-140)  then again TN can possible?

3.       If Greencard (I-140)  is filed and something goes wrong (layoff) and need to come back to Canada in future after 2-3 years and Is it possible to file E2 business visa and can move to USA again?