1. A “vithi” means a “series.”
– A single citta NEVER arises in mind.
– A pancadvara citta vithi arises due to a thought object that comes via one of the five physical senses: eyes, ears, nose, tongue, and body. It has 17 cittas.
– A manodvara citta vithi arises in the mind. It can have a variable number of cittas, but the minimum is about 12.
2. Any single citta goes through that 9-stage process. Yes. It is amazing.
– Of course, only the mind of a Buddha can “see” such fast processes.
– Each person can accept (or reject) such analysis based on the level of faith.
– I accept it not out of blind faith, but I can see that Buddha’s analysis is self-consistent and can explain many phenomena in great detail. To get to that stage, one must spend time and understand Abhidhamma. I have recommended a couple of books in the post, “Abhidhamma – Introduction.”
P.S. Of course, it is not necessary to learn Abhidhamma. Learning Abhidhamma just makes it possible to investigate phenomena at deeper levels, and thus get a deeper understanding.