At long last! My Mini's officialy unconfused now. It's no longer mistaking itself as a Compaq Mini at boot up, thanks to afudos.
As I look back at my little experiment with bios editing via DMI edit, my guilt / conscience is racked with "shoulda-woulda-coulda" (kinda like an All Saint's song, huh?).
1) If I had downloaded the afuwin utilities from this link, shoved it in a bootable USB key (which has become bootable because of FreeDOS; more on this in a later post), I could've backed up my Mini's original bios as a .rom file on this same USB key.
2) Then I could've edited my bios with DMICFG.exe, running from the same bootable USB key without any worries at all aside from, of course, carefully following the guide on which particular info I could chang; no more, no less.
3) So, the moment I realized that editing my bios for it to pretend to be a MacBook2,1 or a MacBookAir1,1 didn't help just like all AppleSMBIOS, SMBIOSEnabler, SMBIOSEFI kexts that I'd tried previously, I should've been able to just boot into FreeDOS again grâce à la same USB key and type in the prompt:
C:\> afudos.exe <name-of-bios-rom> /p /b /n /c
and hit Enter.
4) After that, I could've just reboot the Mini and find my HP logo restored in all its blue glowy presence.
But then again, I wouldn't have done what I did if I could've just been less of an obsessed hackintosher.