Redundancy can actually be useful in notation as a sort of error-detecting code. In this case, if the pitch-symbol and pitch-position don't match up, someone must have made a mistake in transcribing it.
Whether it helps one when reading music is another matter. I remember learning to play an electric organ as a youngster with a book of sheet music that came with the organ; being aimed at beginners, each note head had the note letter written inside it. Hummingbird is basically using the same idea, just replacing the letter with a symbol. It probably does make it easier to learn. Whether it would be of any use for an experienced musician, I kind of doubt. (I certainly outgrew expecting the note head to contain the note letter, myself.)
It depends on the purpose. Introductory materials sometimes use a large enough note that they can write the letter name inside the note head. (Works better for black note heads.)
The redundancy helps associate the name and position.
I don't think I would prefer it in this case. The extra note name information is visually noisy and detracts from the shape of the line, which is mostly what experienced musicians see. The shape of the line, the absence of sharp and flat marks, and remembering what key you are playing in, covers most of your reading.
not really, it can help in reading things faster&reduce errors and in this case the standard notation is just "wasting" some bits of information (the shape).
But, I, for one, am annoyed by the english language needing both grammatical structure _and_ a question mark to express questions ;)
