1)
Why did they mention Nebuchadnetzar's name?
1.
Rashi: If you want us to accept your decrees to pay taxes, you are king over us. If you want us to deny Hashem, you are Nebuchadnetzar ? a lowly person in our eyes, and [from] a disgraced nation.
2.
Malbim: For this you are not our king. you rule over our bodies and land, but not over our Neshamos, in what pertains to our creed.
2)
What is the meaning of "Lo Chashchin Anachna"?
1.
Rashi: We need not take counsel what to answer you. Our answer is ready!
2.
Ibn Ezra: We need not answer you. Our G-d that we serve can save us.
