Regarding 3, I've always thought that was a weak justification for listening more and speaking less. I agree with the moral, but the same logic can be applied to arrive at a number of ridiculous conclusions.

Regarding 4, Yes. Absolutely. The art of conversation is a delicate one, and I've witnessed the 'hold the reigns' phenomenon often. (I'm one of the worst offenders.) What's helped me is to imagine what my point and the supporting statements are before opening my mouth. If I know what I need to say before I start speaking, I'm less likely to ramble until I'm satisfied my point is made.