We've been sending many applications without the fee and having no issues. Our case wont be rejected, that I know and I will be writing a full post on why once she completes the N-400 process. Ive documented in previous postings where I have not sent in previous tax forms, left supporting documentation out, and at each phase along the way we are approved with nobody asking questions, either at the I-485 interview as well as the K1 interview at the Embassy. There have been zero questions in 3 years. Once her N-400 is approved I will provide a whole case summary. I have received more questions during my renouncing of US citizenship then she has received during her US immigration process.