I do not want to use mac OS at all, I just like the hardware.
I dont want to use Paralels or Boot Camp. I think that it is possible because both Macintosh OS and Windows run on x86 or x64.
Windows 7 (both 32 and 64 bit version ) can be installed natively on a Mac in BIOS mode on a MBR style disk.
Forget installing with BIOS mode on a GPT style disk, that only works in UEFI mode.
Since your mac mini comes with UEFI enabled by default, you will need to change this and you will need to change the format on the disk.