help booting live media on MacBook Pro 8,2? (hoping for dual boot)

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I have a MacBook Pro 8,2 (early 2011). It's running macOS Sierra, and I would like to dual boot Fedora 25. I currently have 400GB free space on the drive, but can put a partition there if it would help.

I'm trying to follow the instructions here. I already made the mistake of trying to use a DVD, but that seems to not work because I was booting with CSM-BIOS. I mention this because I had no trouble getting GNOME or Anaconda running graphically, and also I've done a successful single-boot install via DVD on this machine. Now I'm trying a USB installer created with Fedora Media Writer, so I'm booting with EFI.

Trying to boot normally, I just get a white screen. If I go to tty3 and then back to tty1, I can see various normal startup messages followed by "vgaswitcheroo: client 0 refused switch" and then "vgaswitcheroo: client 101 refused switch". I also tried Troubleshooting mode, which did not lead to the white screen or the error messages, but showed a lot of successful-looking OK startup messages and then just sat there with the messages on the screen. (I cannot get to the other tty's in this state.)

This seems somewhat reminiscent of this old F20 bug, the discussion of which is largely over my head. But I tried putting nomodeset in the boot options for my USB live media. But I couldn't proceed because the control key wasn't registering in that state, so I just kept typing "x" when I wanted to press Ctrl-x to boot.

Following Chris Murphy's prior suggestion, here is the link resulting from cat /var/log/anaconda/program.log | fpaste, here is the link from cat /var/log/anaconda/anaconda.log, and here is the output from efibootmgr -v:

BootCurrent: 0000
Timeout: 5 seconds
BootOrder: 0080
Boot0080*   PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(3,GPT,7c6a6cc4-f3e4-4792-a4a0-a8f1a2163d3f,0x574107a8,0x135f20)/File(\System\Library\CoreServices\boot.efi)
Boot0082*   PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(3,GPT,7c6a6cc4-f3e4-4792-a4a0-a8f1a2163d3f,0x574107a8,0x135f20)
BootFFFF*   PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(3,GPT,7c6a6cc4-f3e4-4792-a4a0-a8f1a2163d3f,0x574107a8,0x135f20)/File(\System\Library\CoreServices\boot.efi)

Thanks for your help!