Answers:
1) She can possibly be denied re-entry as a Visitor because her intent to remain permanently. However, that's probably not going to happen. She's Dutch, so she's visa exempt. If she takes proof of her PR application and proof of Financial Support, then chances are, it will be fine.
2) No
3) Yup, that's perfectly fine. You don't even have to technically enter the USA. You can also check with your local office for an appointment. Sometimes they surprise you.
4) Even if she requires an interview, she still has to do the landing in Canada
1) She can possibly be denied re-entry as a Visitor because her intent to remain permanently. However, that's probably not going to happen. She's Dutch, so she's visa exempt. If she takes proof of her PR application and proof of Financial Support, then chances are, it will be fine.
2) No
3) Yup, that's perfectly fine. You don't even have to technically enter the USA. You can also check with your local office for an appointment. Sometimes they surprise you.
4) Even if she requires an interview, she still has to do the landing in Canada