I would take a serious look at the Pocket Cinema Camera 4K if you don't have to have SDI. That thing is insanely impressive and does some things better than the Ursa mini. Just get the Metabones Speedbooster to adapt MFT mount to Canon EF mount and you are set.
Would not reccomend the 846. Shure IEMs are not very good. They were good for their time, but they have been majorly outclassed. Take a look at the Campfire Andromeda or Hyla CE-5.
Using the WH1000XM3 will sound bad on anything when using 3.5mm, DAC/Amp regardless. That is because the internal amp has a DSP correction in place that is needed for them to sound correct.
Not a fan of the Game Zero from memory. Game One or PC37X from Massdrop is better if you MUST have a headset. Otherwise Headphones + Mic is better option.
If you like a very warm and dark signature. The LCD-X is the darkest of the LCD line. Also the older pairs had massive FR discrepancy between pairs. If you have a good pair they are pretty good, just really dark.
Yeah don't do that. It will sound horrible. Most voice chat applications let you share system sound. Which I still can't understand why you would want to do that, but if you want to you can.