Hi, these are not bad ideas, but I think you strongly underestimate the programming effort required to do any of them correctly. So they're not bad ideas, but given that we have a lot on our plate (for instance networked multiplayer) it's unlikely that we will have time to work on most of these ideas soon
One exception though, after the release I plan on working on enabling scripting, which was worked on during GSOC 2014. This feature could enable idea #1 - so this one is probably coming
Also #4 is definitely not something we want to fix through powerups
We are aware that some STK tracks used to be too dark, but in the new version most of them have been adjusted to be much less dark (on a reasonably well calibrated screen)