1, I like the style of the face very much, so I can't grasp the wide structure of the words when I write hard. If you want to write beautiful hard pen calligraphy while practicing soft pen, I recommend you to practice European style. Nowadays, people practice face more than European ones.
2. Note: Never practice at the same time. Because of the different styles, it is easy to confuse the two writing methods if you don't grasp them well. Also, it's best to copy some unrefined copybooks on the tablet, which will be more real and natural. P.S. About the introduction you asked: European strokes are difficult to control, and the introduction may be slightly more difficult than Yan style.
3. But it depends on the individual situation whether it is difficult first or easy first. The strokes of Yan style are rich and full, while those of European style are natural and natural. My calligraphy teacher recommended me to use Yan Ti, because I have a lively personality, and he recommended those cautious and introverted students to learn European Ti. So it all depends on personal circumstances.