I used to work as a Barista.
I don't think I could ever be a barista and make all those different espresso-based drinks.
Yea it is a lot of memorization of adding different ingredients.
Although it may be relaxing to work in a coffeehouse where they serve hot coffee, tea, and sometimes food.
Yea there are lots of time for relaxing when you are not dealing with customers.
Actually all coffees are based on either espresso or coffee. There are different strengths and some have milk or cream and some don't. 
That is true, do you like cofee? You seem to know a lot about it.
Iced coffee
Iced coffee is a type of coffee beverage served chilled, brewed variously with the fundamental division being cold brew – brewing the coffee cold, yielding a different flavour, and not requiring cooling – or brewing normally (hot) and then cooling, generally by simply pouring over ice or into ice cold milk. In hot brewing, sweeteners and flavourings are often mixed into the hot coffee before cooling, due to faster dissolution in hot water. Alternatively, syrup (sugar pre-dissolved in water) may be used
Barista
A barista (; ; from the Italian for "bartender") is a person, usually a coffeehouse employee, who prepares and serves espresso-based coffee drinks.
Etymology and inflection.
The word "barista" comes from Italian, where it means a male or female "bartender" who typically works behind a counter, serving hot drinks (such as espresso), cold alcoholic and non-alcoholic beverages, and snacks. The native plural in English is "baristas", while in Italian the plural