Mature-looking handwriting reads as fluent and confident, not careful and labored. You can't trace your way to it, because tracing looks effortful. Fluency from memory is what looks grown-up.
Reading emotional stress from how fast you write characters is graphology, not science. Stroke speed reflects fluency and the task, not a reliable signal of your emotional state. Here is the honest take.
Writing speed is a result of fluency, not a target to chase. Optimizing a speed metric directly can wreck accuracy, and reading personality from speed is graphology. Here is what to measure instead.