"That person is caustic," means "That person is sarcastic/mean/harsh." If someone says something "caustically," it means that they are saying something in a sarcastic/hurtful way. Hope this helps. :-)
The statement true and I tend to agree to the fact that, they are always slow and always cool. This is because, low rider bikes takes into consideration their environment and those other riders before and during their bike riding.
<em>They know that, riding their bike in a fast and furious mode rather than slow is prone to accident which might be devastating to both them and the next person walking along the pedestrian road.</em>
"When doing a persuasive speech you have to keep in mind that you want to convince the audience to believe in what you are telling them, or support your claim, in this case you are already biased by this desire, the key to persuade people is to know how to convince them, and you can do this easiyl with strong writting and a powerful delivery."