Nora gets tractored by Plutt and then rins into him, getting two tractor beam tokens. Each token reduces Nora's AGI by one "to a minimum of zero".

Zuckuss then rolls up and uses his ability giving Nora an extra defense die. Does she get it?

Me thinks yes, but am not sure.

The 2nd tractor would counter any bonus to her agility but not "roll extra green dice" - as thats not the agility stat.

Yes, she does, because the extra defense die is not agility.

Your agility determines the base number of green dice you roll. Additional green dice can be added by other effects, such as the shot being obstructed. The classic example is a Decimator using Expose and hiding behind an obstacle- it reduces its agility from 0 to 0, then gets an extra green die from the obstacle anyway because obstruction doesn't reference agility.

Yes, she gets to roll the Zuckuss die, but not because of the way "to a minimum of zero" works. She gets it because the Tractor Beam tokens are modifying her Agility, and Zuckuss is modifying the number of green dice she gets to roll.

If Zuckuss increased her Agility by one, then the second tractor beam token would indeed cancel out the benefit, because the "to a minimum of zero" doesn't get applied until after everything that's modifying her Agility is figured in. This would leave her still with no green dice (barring Range or Obstruction bonus dice, which also get added after the Agility number is calculated).

But Zuckuss doesn't modify his target's agility, he grants them an additional die.

Citation: FAQ 4.2.3, p4 "Increasing and Reducing Values"

Yes, the way it works is laid out in the faq.

First thing you do is determine agility value, this is from tractor beams, base value, etc. This is where the minimum comes in. If Nora has 65 tractor bean tokens she will sum her agility modifiers, get -64, then apply the minimum to 0.

Second step is add dice to the pool from step 1 by applying range and other bonuses. Here is where obstruction, range 3+, Zuckuss pilot, and any other 'roll additional defense dice' effects occur.

In the listed scenario:

Step 1) 1-1-1 = -1 => 0

Step 2) 0 + 1 => 1 green die rolled.

Although you need to not where the "minimum of zero" is applied I take it as meaning "treat a final result that would be less than zero as zero instead."

A rules question reply states that the adjustment to agility calculation is made and ends with a minimum of 0 value then any bonus die (ie obstructed, range....) are added. So you can end up with a -3 agility value (starting with 0 agility, then add two TB tokens plus a structural damage crit card) and still get to roll both a range 3 bonus die and an obstructed bonus die if they are both available.