Answer to Question 1
Green tea Leaves are not oxidized or fermented, which results in a lighter, greener tea.
Black tea Leaves are withered and dried under hot air before rolling. When rolled, enzymes oxidize the polyphenolic compounds, which alters flavor, color, and aroma.
Oolong tea Leaves are partially oxidized; they are processed between green and black tea and may be flavored with jasmine flowers.
Decaffeinated tea Tea without caffeine.
Herbal tea Tea beverages that technically do not contain tea leaves; they are prepared from a wide variety of leaves, flowers, barks, and/or fruits of plants. They are called herbal teas because they are prepared similarly to tea.
Answer to Question 2
These materials do not have any interactions with the coffee or alteration of flavors or taste.