I'd just like to add a final word of special thanks to Draygone, whose playthrough has really brought a lot of the demo's elements with which I'm not 100% happy into focus.
I'm working on version 29 now, taking into account his findings and the suggestions of Devourer51 here on rpgmaker.net. I've felt too certain that the demo was 'finished' for too long and it feels good to have found new areas to move into and work on.