To answer your questions, you have to understand the biological responses by the body. Although the penis compose of 78% soft tissues, it doesn't mean the soft tissues don't react like hard muscle tissues. There are short and long fibers in your soft tissues. When you stretch short fibers, the fibers relaxes, and over time, the short fibers lose elasticity. Short fibers are known for its fast responses, or twitching fiber tissues. Longer ones response a bit slower, but balance out the short twitches by compensating with reinforcement.
Think about when you're stretching downwards. The short fibers at the upper length of the penile will eventually relax and lessen in strength over time. The lower length short fibers will remain stronger the upper. That cause the penis to point down during an erection as the fibers pull during and erection. This is why you wan to balance out the stretches upwards and downwards.
Same is true for when you over exert the upper and lower tissues. the short fibers along the sides of the penis now are stronger than the upper and lower. During a strong erection, there may be a strange development of the penis curves left or curves right, depending on where the stronger short fibers are located at. You may even develope a strange S-shape penis during an erection. I saw a few of these. The side pulls reduce such a phenomenon. The helicopter bundled pulls also reduce this development.