First let me preface by saying this is not a criticism - I love your
enthusiasm for tea!
You know what I think? I think you need to try a Darjeeling.
(Or oolong, of course)
From what I am reading it seems you, in most cases, are
trying to reduce the strong bitter black tea taste by additives
or chocolate. Keep in mind that flavored teas typically don't use
the best quality tea to start with because they know the flavor
will help mask it.
There is nothing wrong with flavored teas per se, I just think there
is a whole world of quality tea out there and you are trying to make
the lesser tea taste good, rather than seeking better tea.
That is all for today, Grasshoppa.