yes, yes and yes. Shiyet can happen anytime. The people behind adsense are humans, and an algorithmic logical AI, these are prone to mistakes too. Like what has been always said, don't leave all the cards on the table, yes adsense can be a good source of income but it's not secure like anything else in this world, have it spread around, do some online jobs, other advertisings or source or something not to make adsense 100% source of income, 60% maybe is enough
If you are entrepreneurial by your nature, you should quit your job. Very, very few jobs pay as much as you could make doing the same thing self employed. Even jobs you wouldn't think about that way. A cop could own a private security company, teacher could be a private tutor to rich people's kids. What is your job, and why do you want to make someone else rich? You keep your job out of fear. If you quit, you will have the fear of losing adsense. Neither is perfect. Quit now, and use those extra work hours to expand and diversify your income. Good luck.
No sir never.. If you have few more earning source than adsense like any other ad network and affiliate earning then you can leave your job but leaving your job only for adsense alone is very risky.
If you do any mistake in click or anything which is against rule then google will be banned to you immediately.