Employer considering to transfer me to US on L1A. I have TN work authorization, and live in Canada.

If the requirements are all met, then yes. Your employer needs to retain an experienced immigration lawyer to review all the facts, advise them,...

AOS through Family Petition F1 and 245i, priority November, 2006.

Maybe, maybe not. The Court of Appeals for the Ninth Circuit has stated that immigration laws are "incredibly complex" in nature. You should...

H1B with COS 2014 processing

A decision prior to October 1 is not guaranteed. You can only start working after USCIS changes your status. Your employer needs to retain an...

Probably Ok. The Court of Appeals for the Eigth Circuit has stated that "immigration laws and precedents are complex." You should retain an...

About withdraw change of status from B2 to H4, when it is pending

Yes, you can withdraw it. The Court of Appeals for the Ninth Circuit has stated that immigration laws are "incredibly complex" in...

Can I really enter " now" with h-1b visa?

No. The earliest that you can enter is September 20th. Your employer needs to retain an experienced immigration lawyer to review all the facts,...

My L1B visa & I-94 got expired on 11th July 2013, and applied for Extension to recapture my absence of US stay in entire 5 years

Recapture is possible. Your employer needs to retain an experienced immigration lawyer to review all the facts, advise them, and handle the...

F2A categories

Unknown. It depends on when you filed and how far the category retrogresses in October.

Yes, if you are maintaining valid status, but that will delay your becoming a permanent resident.

Should I wait for I-539 decision or leave before the decision?

"Should I wait for I-539 decision or leave before the decision?" Only you can make that decision. Your analysis of the choices is correct.