1. No
2. I ran mine through the unused grommet intended for the trailer hitch wiring harness (in the image below)
3. Not without great difficulty. The unused slots do not have contacts soldered to the circuit board underneath. If you were extremely motivated, you could take a fuse box out of a junkyard Pac and salvage connections from it. You would then need to remove your fusebox and disassemble it and solder your salvaged connectors to it - IF you could find a live spot, which you may need to do some reprogramming to accomplish. I am not saying it is impossible, but only the truly motivated would be willing to expend the effort. It would take hours of work.