Only the USCIS officer making the decision can decide whether it will or will not be denied.
Who files for divorce is completely irrelevant.
You should retain an experienced immigration lawyer, whether myself or one of my colleagues, to review all the facts, advise you, and handle the case.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
It would all depend on the totality of the evidence provided when filing the I-751.
It is very difficult to say what type of impact it will have on the case, without seeing the divorce documents (complaint, decision, etc.) and evaluating the proof that the marriage was bona fide.
The foreign spouse should retain an experienced immigration attorney to evaluate and prepare her I-751 case.
No, the alien can file for divorce, and need to prove who is at fault.
The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.