super+F5 is the system-wide shortcut to toggle VoiceOver, an accessibility tool (on Yosemite, at least).

There's no way to disable this system-wide shortcut. When I type it in SublimeText3, it doesn't even register with ST3 or InsertDate. It just opens VoiceOver, and that's it.
Also, I don't know if I'm being stupid, but it won't let me edit the default InsertDate keybindings, and there is no "User" file for me to override them with.
But I think the real problem is that these are the defaults at all, since they can't work on OS X.