Make macro commands where you can step fast forward/backwards through the markers.
Macro: Marker Forward by 2 times:
1 Marker | Goto Next Marker
2 Marker | Goto Next Marker
Of course you can use this command by 10 times and you get an "goto end marker". You can replace the NumPad7...9 shortcuts with these new macro commands. In a similar way there are other macro commands like "Goto Next Section" and "Goto Previous Section". Create your own shortcuts for these commands or make a nice user macro page (maybe with your own icons).