@Real Deal - this may get you close to the answer to your 2nd question:
While it relates to receiving an errant 1099K, it is very similar to what you are asking.
if someone was to receive an errant 1099K, the IRS states to report that 1099K as normal and then turn around and zero it out by reporting it as an 'other adjustment; on Form 1040, Schedule 1, Part II – Line 24z and indicate a short reason. look at the 2nd page of the link below.
https://www.irs.gov/pub/irs-pdf/f1040s1.pdf
on your first question, and this is just my opinion, and I confident others will chime in, the IRS defines a gift as
"You make a gift if you give property (including money), or the use of or income from property, without expecting to receive something of at least equal value in return"
So I could see the arguement that Amazon doesn't see this as a gift as they ARE expecting someting of at least equal value in return (the product reviews). and if it isn't a gift, then what is it? income? Also, I wonder if how all those questions were answered on the form you filled out for Amazon brought them to the conclusion that they had to issue a 1099NEC. Certainly Amazon didn't put that set of questions together without a purpose (and without lawyers involved!),
