So I was finally able to install 10.11.1 on with Pike's fixes and the USBInjectAll.kext (following the Skylake starter guide, basically), and here is the status:
1. SATA ports work and are all detected
2. Graphics shows up as "Display 7 MB". Weird artifacts happen when the UI opens for the first time, and FPS drops in the launchpad etc. Guessing I will have to wait for AMD R9 support to show up? I found a thread that talks about a fix for R9 390 working on a 4790K setup, but I'm guessing motherboard issues would make that inapplicable here.
3. No audio, or ethernet (I have the I-219V, so this was expected). For some reason, I can't get any of my USB wireless devices running either. I installed the drivers but the "configuration utilities" just don't open, and Network preferences crashes back to settings: so pretty much no internet for now
4. USB3 flash drives do not work.
5. System memory is detected correctly.
Given that I have the Realtek ALC1150, can I go ahead and try toleda's audio fix? Does anyone have suggestions about the GPU? In System Report, the graphics says "Vendor: ATI, Device ID: 0x67b1" but the memory is still 7 MB.