Form 1040NR - Amount You Owe and Occupation

[ErinErin]

I'm filling in Form1040 NR.
I have a very small amount from US income and I'm submitting the form to claim a refund for federal withholding. As a result of all calculations on the Form 1040NR I get a negative amount for line 75. I know that I don't owe anything to the IRS anyway due to the previous withholding, is it OK to enter the negative amount? Or should I leave that field blank?

In the Sign Here section, there's "Your occupation in the US" field. I wasn't in the US during the tax year, should I enter "N/A" there or should I enter my occupation overseas? How important is that field?

Thanks a lot for any advice!