Answer A.) There’s no easy way to eliminate visible pinch points on the final product, but bottom loading has provided good results for me personally. When bottom loading, you may want to pull sweeps out for even cleaner results.
Answer B.) Pinch points are relatively normal, and they go away with heat. That being said, pinch points can become more noticeable if the tinter is relatively inexperienced. You can cut down on the severity of pinch points with time and training, but it’s not a big deal, and removing them with heat simply adds another quick step to the overall process.
Answer C.) If bottom loading is too advanced for you or if you’re still learning, you can always try adding a little more slip solution. This should minimize the appearance of pinch points.