As to your first question, true holiness is the manifestation of God in the life of a believer. Only God can produce this kind of holiness, and only a genuinely born again person can manifest it. All other holiness is artificial. Good character does not have meaning outside of holiness. In the world, some people are said to have good character yet they do not act consistently with biblical precepts. What we ought to talk about is not 'good' character but 'godly' character. This is the kind of character that is modeled after God's own character.
As for your second question, any person with genuine holiness will have good/godly character. The absence of godly character equals the absence of holiness. For example, some people believe they are holy because they dress modestly and attend church services. Yet they scream at their spouse and tell lies at work. These people have artificail holiness, not the real thing.