Best case: it runs perfectly fine.
Worst case: bricked.
You're playing with fire and the consequences are undeniably worse than simply unlocking your bootloader and doing a custom ROM. Also, AFAIK, the rom.zip file is not formatted the same as any ROMs available right now, so you'd have to recompile them into .IMG files.
Sent from my HTC Velocity 4G using XDA Premium App
Goodbye XDA, you won't be missed. Never have I seen a lousier Android community unwilling to take care of its devs.
Also, give me a refund for my XDA Premium app.