Temperature will really depend on the type of tea. Black teas/Puehrs usually have hotter water while greens will tend to have slightly cooled water. But even within types of tea you will have varying temperatures... for example Gyokuro green tea does better with MUCH cooler water than other green teas. it all comes down to experimentation and your own individual taste. Personally, I only use a thermometer on the more expensive/finicky teas like gyokuro because in these cases I want to be sure I have the temperature as close to optimum as possible... but most of the time I just wing it
Oxidized will have a few different meanings I suspect when it comes to tea... I will leave the detailed explanation to the Black Tea/Oolong experts. Green tea however is unoxidized, which is partially why it is now en vogue and added to everything in one form or another for it's supposed health benefits.
Matcha is different from most types of tea. It's traditional Japanese ceremonial tea... and it takes a bit of getting used to
some people love it, some people hate it... but it's worth a try at some point, as long as you can get your hands on a good quality matcha. Most (all?) matcha you would find in a grocery store, even an asian grocery store is pretty low quality food-grade tea which will typically be rather bitter. there are plenty of tea websites where you can order good quality tea though. Matcha, moreso than other teas (well, depends on who you ask...
) involves the use of specific instruments... like the bamboo whisk, scoop, and special tea bowl. again, this is all originally ceremonial... with meaning endowed to everything.
