Ok, it's my take, partly as a response to our off-list conversation with Richard Haynes.
1. One single line of melody, the flats marked by putting a circle around them, something that is quite easy to reproduce in handwriting or in word processing.
2.Numbering , where we agree that the open string is the prime, and then the first key is the second note and so on (primo, secondo, terzo, etc.). I think it is good because it does relate to something that is commonplace in music, i.e. the intervals, and why not offer a system, which then can be related later on to traditional music ideas if somebody (like our Mark Hewitt on the forum) decides to study music theory.
3. Continually growing numbers after reaching the octave, this is also consistent with the traditional interval system (nona, decima, etc.)
4.I have been experimenting with different staves and tabs, I wanted less lines and better visuality. I accidentally came across with this tenor banjo tab, which is not only 4 lines, but Sibelius actually puts in the rhythm in a very simplistic form as you type the numbers. It's a good use of stick notation and again very easy to reproduce in handwriting or even in word-processing.
"si tacuisses, philosophus mansisses"
"ha hallgattál volna, bölcs maradtál volna"
"if only you had kept quiet you would have remained wise"