"(1) As I have to pay AMT on the NSO in 2016"
The exercise of non-qualified stock options is not an AMT preference item or an AMT adjustment so you didn't "have to pay AMT on the NSO(s)". The ONLY way that could have happened is if you entered the exercise in the "ISO Exercise and Hold" interview, in which case you need to go back and amend 2016.
Perhaps you were subject to AMT in 2016 but you can't really "attribute" that to the 2016 NQSO exercise, in the absence of the mistake I mentioned above.
"can I do I enter the tax paid for 2016 as a tax credit for 2017 in turbotax"
You don't for the reason stated above.
"2) Is there a way we could use my capital loss carry-forward from
historical stock sales (separately from the NSO) on Schedule D to offset
the gain from the NSO either in 2016 or 2017? "
You had no "gain" in 2016 you just had "compensation" from the exercise. Assuming the 2017 sale was at a gain any capital loss carryforwards from 2016 and before will automatically be applied as an offset.
Tom Young
