My lexicon says that this is a feminine PASSIVE participle from the verb, charitoo ("caret-ah-oh") meaning, in the active voice, to make [someone] an object of favour, to gift [someone]. IN THE PASSIVE VOICE, to be an object of a gracious visitation or to be visited with free favour. My comment: No emphasis is placed on the character of the person visited; instead, the emphasis is on the disposition of the visitor.
According to Jeffrey A. Rydberg-Cox's, Overview of Greek Syntax:
Active Voice: The active voice denotes that the subject is the agent of an action.
Middle Voice: The middle voice denotes that the subject is both an agent of an action and somehow concerned with the action.
Passive Voice: The passive voice denotes that the subject is acted upon.
With that said, your comment that "No emphasis is placed on the character of the person visited; instead, the emphasis is on the disposition of the visitor." makes no sense. Mary is the subject acted upon by grace, not the Angel. In other words, the word kecharitomene is completely about Mary. She is the subject of the verb, not the Angel.
Pray for John Paul II