Legal Question in Employment Law in California

Discrimination? Yes. Illegal discrimination? No. They are free to chose which felonies they disregard and which they don't. They don't have to hire all felons just because they are willing to hire some.

No, it's not discrimination. There is nothing stopping a company from not hiring a felon. Sorry about that.

NO. felon is not a 'protected class' such as race, age, sex, religion, etc. You will have to live with the adverse consequences of your earlier unwise decisions for the rest of your life. The longer you remain 'clean', the better you will fare in employment. You will need to develop a truthful explanation to provide employers that will persuade them you are worth taking a chance on, because you have turned your life around now. Not everyone will turn you away.