I'm not Dickey, but I can tell you the reason why so many advocate holding off on tren until a couple cycles are under your belt is so you know what to do if a problem does arise. Roid rage is a myth in my opinion, but AAS DOES amplify what kind of person you are. If you feel a great deal of aggression from testosterone, you might be a very angry or short-tempered person while on something as potent as tren. Knowing that you're susceptible to this type of side effect would help you to prepare for something like this in case it happens. Another example would be possible estrogenic/prolactin sides; if you get gyno (prolactin can cause this as well) easily, it would be helpful to know this so you can prepare ahead of time, knowing what the symptoms are so you can prevent any problems before they occur.
I've been lucky so far in my experiences with tren, but I can't imagine what would happen if I developed the dreaded "tren cough" without having my injection technique perfected and having experienced everything from gushers (nicking a blood vessel) to hitting a nerve on more than one occasion. I would probably freak out and potentially injure myself with that tiny piece of steel firmly implanted in my leg/delt/ass. Experience helps with these types of situations so you are able to calmly and cooly react properly.
Are the sides over-hyped? Maybe for us lucky ones, but for those poor bastards that find themselves getting all the sides, I think it serves as a great warning so they can try to be ready for whatever may happen.
My .02c