1. I believe writing emails and letters are very easy for me personally, but I also take into consideration that sometimes face to face conversation might be better for the other person... so I force myself to do things that way depending on the person.
I wouldn't let something go on for too long. I'm at the point in my life where I try not to push things off for a later time because I feel like time is too important to waste, but when I was a kid... forget it. I would let things linger and linger until they fell into place and they typically did... but those days are over.
2. I can't say I've ever prepared well for a confrontation, but I think sometimes they happen when you least expect them to or want them to (though you never want them to happen in the first place).
It all depends on the person I'm dealing with. Whether they have an issue with me or I have an issue with them -- and a lot of the times for me, the other person, no matter which way I deliver it, doesn't want to understand me. But it's true -- sometimes I'll snap like a short fuse and insist that what I think, I think strongly. Other times I'll tensely pace myself and deliver it as calmly as I can and shrug it off like it's not a big deal... though my shoulders are tense as hell.