Yes, that’s normal. There was never a problem with Win8 booting without secure boot. I’m not sure, but maybe it complains. I don’t use Win8 often enough to have noticed any complaint. But then I have secure-boot enabled most of the time.
oS 13.1 DVD is recognized with secureboot enabled. With Partition Magic it wasn’t. At startup, the BIOS reads the DVD, and if there’s no disk inserted the drive won’t appear in the boot options. So I’m presuming the BIOS checks the disk on the DVD and only enable it if the boot record (or whatever) is certified, as I understand openSUSE 13.1 is.
I always use a USB (write the iso to a USB). That’s also recognized as secure-boot.
If I disable secure-boot, and hit F12 while booting, my BIOS gives two lists of boot possibilities. The first list is of UEFI bootable systems, while the second is of MBR bootable systems. The “partition magic” CD would show up only as MBR bootable. I do have a CD with “Acronis True Image” (the 2013) version. It shows up in both UEFI and MBR lists, as does the 13.1 DVD image on USB. However, the Acronis CD does not show up if I enable “secure-boot”, because they did not do the extra magic needed for that.
For a hard driver or USB, in order to be UEFI bootable, there must be an EFI partition containing an efi executable in the right location in that partition. For secure boot, that efi executable must, in addition, be digitally signed with a key known to the BIOS.
I’m not fully sure of what is required for a CD or DVD. My understanding is that the UEFI bootable CD or DVD typically contains two floppy disk images. One of those has the EFI stuff, and the other has the code to boot the operating system, perhaps as called from efi executable on the EFI floppy image.
More or less. EFI bootable CD contains El Torito boot image with special type (it is not floppy emulation) which is basically image of EFI System Partition. Inside this El Torito image you have standard ESP directory layout with \EFI\BOOT\BOOTX64.EFI (or BOOTIA32.EFI) and any other files required by bootloader. This El Torito image is exposed by EFI firmware later as media device (you can e.g. list content of it in EFI shell), but grub2 does not use it and expects all other files to be present on CD in normal iso9660/UDF/whatever filesystem.