Removing the key signature is not a good idea. When playing in G major, the sharp accidental on the Fs is not put at the beginning of the line just to avoid printing it in the score. Rather, it fits there because when I play in G major, I put my brain in G major mode, in which case it would be distracting to have an accidental on every single F.
Similarly, writing a special symbol for each pitch seems it would get heavily in the way of transposing on the fly. The position already encodes the pitch, and the ABCDEFG names kind of get in the way of understanding the melody, which is more about relative intervals than absolute values.
And what does the little parenthesis on the length line mean? For half- and whole notes it seems to mean it doubles the length (a quarternote with one or two parentheses), but for sixteenth-notes it seems to indicate that it halves it (an eighth-note with a single parenthesis mark).
I also question removing the stem of a note. I have a feeling that is one of the stronger queues for reading rhythm. Spacing is not very important, and indeed especially in dense scores for solo instruments, that need to have few page turns, notes are often just spaced as tightly as possible.
The author also recognized that the beams on eighth- and sixtheenth-notes (e.g. in the left hand) are very important rhythmic cues, and replaced them with that horizontal thing with the arrow on the left. This is a bit hard to read though when there are no stems to link them to the note and the pitch interval is big.
The part about it being easy to write by hand looks good, and made me feel good at first. Then you realize that hand-written traditional notation is quite different from typeset one, just like handwritten text is very different from printed text. Drawing all the little balls and filling in the halfmoon C, up and down thingies seems tedious, when traditionally one writes a simple dot or a little slash instead of the note head.