Color coding & back button sound like interesting ideas (note the way I wrote color? I hate the British version of words containing the pointless "U").
In regards to sound fx & positioning. Actually possible with a bit of scripting. I already wrote scripts for dynamic sound, but don't know if I want to share them on the wiki. I waste too much time writing & sharing stuff for free already. The basic gist of the script is to calculate position of character, position of object & then compare with a percentage based on current position of character over scene total width/height or based on position of character in the viewport.
P.S: here's a few things coming in the next build (the actual changelog is quite large):
* Retina (HiDPI) bug fix
* New option for interfaces (always display - even during cut-scenes)
* New animation frame displacement tool (for offsetting / aligning up animation frames)
* Character speed action part affects walk speed (again)
* Gesture support (phones/tablets)
* & much, much more...