Is It Ever Okay To Walk Away?

I like to think of myself as a good friend...not a perfect friend, but good nonetheless.
What defines a good friend? Time, laughs, outings, talking, sharing, confidence, sympathy, empathy, listening, secrets, understanding, comfort...? What about when you are not getting these things from your "friends"? Which things are not negotiable and which are?
When do you know it's a good time and choice to walk away because the "friendship" is just draining you too much? Is there ever such a time that it's okay?

"You don't have a right to place blame or be angry if you have never communicated that there is a problem. You must give a person the opportunity to change and/or make it right."

That would be one of the statements I believe to be very true. Of course, that would require confrontation which is just so difficult- to difficult. For one, when a situation is brought up and confronted, you leave yourself vulnerable to hear that you may be just as wrong as you believe the other person to be. And two, you risk, and probably will, hurt someone you care about and may even lose them. Walking away is easier in some ways, but harder in others.
Confrontation is a good thing when done correctly. The person being confronted should never feel ganged up on, defeated or degraded. When communicating an issue, it should be done in love and under the covering of a lot of prayer. AND, no matter how disturbed you may be over a matter- you better be sure that God is leading you instead of your emotions and opinions.
If I am a true "good friend", don't I have the responsibility to tell my friend(s) (in love) when there is something going very wrong? Something that not only you are effected by, but others also.

I have one "friend" who isn't my "friend" anymore (yes, this does sound very high school). It came to my attention on Facebook of all places (yes, even more high school). I went to check out her page to see how she was doing and leave a little message when I realized I had been deleted. I thought this just MUST be an mistake, so I requested her as a friend again and then again, and well- it went completely ignored. Now, I don't want someone to be my "friend" out of obligation, but please give the opportunity to either defend myself and/or apologize if I have done something.
This whole thing bothered me the most, because I have no clue what I really did- I have an idea of something it may have been- but I don't know. If I did do something, I was never given the opportunity to make it right. Assuming I did do something wrong, I could of learned, grown and apologized if I would of been given the opportunity (shocking that I am imperfect).
Considering there have been times in my life that I have been lonely without friends nearby, I realize the value of friendships. I do realize that even if I were to distance myself, it is never okay to be hateful or angry- that goes against everything God has instructed me to do in His Word.

So, I guess I have answered my own questions as I type.. Distancing yourself is okay after you have communicated and given the other person the opportunity to explain/change. No one deserves to be written off without explanation or opportunity. Regardless, God requires me to pray, love and care for my friends, even when they drive me up the wall! If I communicate my concerns and issues with my friend, with the right heart, and they choose to continue "draining" me, then that may require some distance- after a lot of prayer.
Proverbs 17:17 says "A friend loves at ALL times.."
Which tells me I better love the good, the bad, and the ugly.............