@Karlos:
Regarding your original problem (reflashing the BlizzPPC without a 15khz monitor):
Reset your machine and keep the ESC key pressed until the BlizzardPPC's own "startup-menu" comes up. Here you can adjust several things (e.g. disable all unused SCSI nodes, this will speed up the boot process).
There's an option somewhere that can redirect AmigaOS' 15khz screenmodes (early startup menu, boot without startup-sequence) to your BVision. It works fine (albeit scrolling is a bit slow) over here.
I could finally get rid of my 15khz monitor after enabling this feature (I have a seperate A1200 setup for nostalgia/retro-gaming stuff).