You seem very passionate about the topic but if you're serious about renderings (and particularly if you base your business on that) you'd be much better served by a computer with a modern nvidia gpu. Not a mac mini with intel "graphics".
Adobe has supported rendering on the GPU with OpenCL (Intel Iris, AMD Radeon, NVIDIA) for a long time now: http://helpx.adobe.com/premiere-pro/system-requirements.html
I went to SIGGRAPH and saw little boxes editing 4K video in Premier quite happily.
Two things though:
1. You need the $699 Mac Mini with Intel Iris graphics
2. I'm assuming the spec is Intel Iris 5100, it doesn't actually say 5100 or 5200 anywhere?!? Pretty sure it must be 5100.
The $499 Mac Mini only has Intel HD 5000, this might be OK at 1080p but if say you are looking to edit 4K video you need the Intel Iris so Adobe uses the GPU. Oh and lots of RAM is nice too for things like editing 4K video, 8GB works, 16GB good, 32GB even better.