Try adding "dart=0" to your boot flags. I would also consider simplifying your system by removing the GTX 950, and install with the onboard HD 4600 graphics. You can add the GTX 950 (along with the necessary Nvidia web drivers) later, once you get through the installation.
If the "dart=0" flag doesn't work, re-make your USB installer. Use a USB 2.0 memory stick, in a USB 2.0 port, and when you try to boot from it in your hack, also use a USB 2.0 port. USB 3.0 (and by extension 3.1) can still be problematic for installation.