1)
What is the tense of "v'Nipatzti"?
1.
Radak #1: It is future; every v'Nipatzti here (in verses 20-23) is mil'Ra (the last syllable is accented). Perhaps this was said before Nebuchadnetzar reigned.
2.
Radak #2: Perhaps this was said after Nebuchadnetzar reigned; future tense can apply to the past.