The sys-r/f are thermal probes for (f)ront and (r)ear of the case. You can place one on the front and compare the temps to the back of your case. The HDD connector was something that I didn't even worry about when hooking up the thing. It will tell you when the HDD is spinning but other than that, it serves no other purpose. I hope this helps you but if it hasn't let me know and I will try to explain it better.
"It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring."
- Carl Sagan
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