Well, I have a multiboot USB Flash Drive, it is
multi-partitioned and it is an MBR based and I successfully booted from it! I think the regular internal drives are not in the screen as an MBR option because they are GPT based.
I have an internal MBR drive in my ZALMAN USB HD 2.5" enclosure and as you can see, it appears on the list so I can boot from. I am sure once I convert my SSD to an MBR drive (and I will during install), it will appear on the list.
I will have to do this later though as I have to go to work now

I will let you know how I go and
you can ask away any questions if you have. This was a big relief from me.
Now that I know what happens, I think I understand why W7 install kept hanging on the logo.
After I clean installed Windows 8, when Windows 8 was launching, it did *not* show me the Windows logo on the splash screen, the flag but instead I kept seeing the ASUS logo all the way until the Windows login screen appeared. So I think there must some sort of internal splash screen in the EFI storage that gets automatically pulled when Legacy MBR is turned
OFF *and* Windows is loading and only W8 has this functionality and it makes the W7 incompatible.
To confirm my theory, I will launch W7 install again in UEFI mode while I have Legacy MBR enabled and see if it works.