cdn69 said:
OK I just checked with my lawyer, I-485 has not been filed yet.
....and since you're doing the consular route, you won't be filing an I-485. I-485 is only used if you would be adjusting your status from within the US.
cdn69 said:
So if I decide to abandon my GC application, is it OK for me to apply for TN visa.
Since you have not filed, and will not be filing, an I-485, you should get future TN's without any problems up until the time that your case is approved at the consular interview.
cdn69 said:
is there any possibility that my I-140 can be taken over by my new employer once my H1 is approved.
You are referring to AC-21 (a.k.a. portability of your I-140) which can only be invoked if you have an approved I-140,
and your I-485 has been pending for at least 6 months. Since you will not be filing an I-485, you will not be eligible for AC-21.
But, since you are filing at the consulate, and as long as your original employer agrees
not to revoke the I-140, then you can keep changing jobs until your green card is approved at the consulate, at which point you
must go work for the employer that filed the I-140.