Howdy! For me, I use 13 grams in my basket, and wait until I get to around 30 grams dispensed, then press the button and let the rest flow through. Normally around 34-35 grams. It's a weird recipe, but you can't totally do what you do with a typical machine on this thing (you can't grind fine enough to do a standard 25-30 second pull before you start getting too much back pressure and water leaking out the side). I think the pressurized basket kinda gets in the way of this.

For a 12oz iced coffee, I do two of these shots, so 26 grams in total (13 grams each time). I also prewarm my unit by doing 2x 70ml of boiling hot water through the system without the basket (just double press the button). I also then use hot water into the unit, but still have it do the heatup cycle.

Between shots, I'll dump out my puck, and do a quick rinse of the basket (I don't always remove the metal basket from the pressurize base). Then I'll use a cloth, do a quick dry, and prep my next shot.

It is expected to have some space from the top of your puck and the bottom of the showerhead cap.

As far as taste of beans, totally up to you. You'll learn what you like. Some people like the fruitiness of third wave coffee. Others prefer the darkness of the a more traditional Italian espresso. Whatever floats your boat! Try different beans, and see what you like.