10 bar on the gauge is spot on - that usually translates to 9 bar at the group. Your instincts are right, 9 bar on the gauge is too fast a pour.
Again with the dose, your instincts are probably right. I usually dose between 18-19g of coffee/double depending on the specific beans and grind etc. I am not very familiar with the K3T, but in terms of routine have a look at the instructional videos on the ECA website, they are very helpful, but your technique sounds like a good start. Remember consistency and reproducibility are the keys. Enjoy you have a great combo. :)