In my opinion, people get too hung over words. It's the meanings, the tone, the body language and expression along with the words that actually speak more than the words that are spoken.
I'm not a very effective verbal communicator. I stumble over words, I say things I didn't mean, I can't recall the words I'm trying to say. It's possible that I just haven't practised speaking enough. It's also possible that I'm just a rubbish verbal communicator
I find it so easy to articulate what I am trying to say here, in written form, the words flow so effortlessly, I'm amazed that I can't talk like this. But then there are certain pressures when it comes to speaking, especially when one is socially anxious.
I would agree that it is always good to think before speaking, whether that is verbally or not. Emotions can cloud judgement; sometimes I'll feel anger about something, and will want to respond in haste, so I force myself to step back and analyse my feelings and my words, and often I don't feel I need to speak about it at all. But then again, I am the kind of person that doesn't speak very much and finds it hard to express myself; living in fear of words and mistakes would only amplify that, and then no one would hear me speak. Expression is a powerful thing, and at its most raw and beautiful state, sometimes it will offend other people, and I believe those people are responsible to how they react to such words, rather than the person responsible for saying them. Sometimes what we'll say will be incredibly stupid and pointless; but isn't that part of the joy of human interaction?