...The rationale is that Holy Prophet (SAW) himself has said that in the later days, Muslims would go astray and a Messiah would come to bring them back to the right path of Islam. And that Messiah would be a Nabi.
Detailed response to your post is not worth my time so I am only picking one fundamental point from your post highlighted above in red.
This is how Mirza saab and his followers twist the facts altering AHADEES and QURAN and that is probably the biggest reason Ahmadis were declared Non-Muslim in the world of 1.66 billion Muslim Ummah.
The red highlighted text above is not what Muslims believe, absolutely wrong and knowingly deceiving interpretation of truth.
RC