Personally, I get around 8 clicks with La Semeuse coffee and a Delonghi dedica EC685.

For espresso, I would recommend the Red Clix thread for a finer (double the number) gradation. I always set around 12 clicks, which corresponds to 6 clicks with the normal thread - but it can vary greatly depending on the bean and filling quantity / sieve. Regarding counting the clicks: you start counting when it no longer grinds/blocks (according to the instructions and various information online).

It all depends, on the type of coffee have and on the way you brew the coffee. I have a rocket machine and for my setup with medium roast speciality coffee 3 clicks are perfect. I would suggest to test it, do a coffe with 3,4,5 and then see which one taste for you the best. At the end of the day you need to enjoy it :)

There is no general grind for all coffees. Each coffee has its own grind. It can (and will) be the case that coffee A and coffee B have the same grind setting, but you can't say 9 clicks applies to all coffees. You have to try it out. It has a recommendation in the manual. Basically: filter coffee = coarse grind. Espresso, fine grind. Turkish coffee even finer than espresso.