[you wrote]
What would a classification based on "script properties" entail, and
why would it be interesting?
[mariano]
Well, the point would be Cognitive Science. To understand the cognitive
properties of writing symbols and systems what then would give light
in why systems are discovered as they are and how and why the change
(and become more and more asbtract with time). But as there is not
known relation between letters and what they represent and even think
that does not probe the opposite it is used to be state as it were true.
Another point in trying to understand writting systems properties and their
way of symbolism if one thinks that writing systems are in a big measure
invented tools is that any invention can be improbed and new systems
developed.