Martin, hi. I see this topic has been idle for a while. Still, the process of restoring archived eCS-2 material to my new AOS-5.1 system has suggested a couple of ideas.
1) Icons have switched from *.ICO to *.PNG, meaning it's complicated to re-use old designs I have come to know and like. PNG is a good format, mind (as it should be, considering its illustrious parentage, NASA &c) but maybe there could be an outwardly simple CLI tool (cf XCOPY, ATTRIB &c) which converts ICO to PNG? Ok, I once had to write code that generated PNG (of heat flow diagrams, FWIW) but left out compression, using PMView for that if I wanted to keep images, so I realise what I'm asking is not trivial.
2) I have long felt it'd be handy if chains of open directories could start with the top level header bar being given a distinctive colour which its children would copy. How about three or four tiny coloured rectangles at one end of the top header: a click activates that colour (temporarily), while a double click invokes a colour palette.
Anyhow, there's some wishing for folks to ponder. Meanwhile, thanks for sterling efforts invested so far.