With debugmode on, It is possible to edit the masterstyle. And it is very possible to do so, because you don't always noice that you are doing that. The masterstyle comes up first when you start editting templates.
So two requests:
- have the mastersyle not come up first. No-one should really edit the masterstyle except for the Xen-guys.
- show the masterstyle-templates in a different color, so you instantly know you're at the wrong place.
Most of what I do template wise is done in the Master Style so on the contrary it would be quite inconvenient it not coming up first by default.
It's just going to be one of those cases where diligence is required.