So, I'm finally getting around to wiring up my IPF 968s and I want to make sure I'm doing this right. A few questions:
1. Can I share the ground for the battery terminal (green circle) with the relay mount? Can I use that same ground for the lights and/or relay? Is the red circled screw an acceptable ground location?

2. This set of wires connects the relay to the switch using the two black wires. The yellow wire is supposed to be used to connect the IPFs to the high beams. I want to use a Toyota fog light switch to control the IPFs. What do I do with the yellow wire?

3. To connect the switch harness to the the Toyota switch, I need to cut off the IPF switch, crimp the wires into disconnects, and connect to the switch, correct? I have red, black, and white wires. Which prong goes with which color?

4. What's the best way to run the wires through the firewall?
Thanks in advance. Wiring is clearly not my forte.
P.S. Here are a couple pages I've been referencing so far for anyone who uses this post in the future with their own wiring needs.
Toyota OEM Fog Light Switch
TTORA - ...ving/Fog Lamps - Faq
1. Can I share the ground for the battery terminal (green circle) with the relay mount? Can I use that same ground for the lights and/or relay? Is the red circled screw an acceptable ground location?

2. This set of wires connects the relay to the switch using the two black wires. The yellow wire is supposed to be used to connect the IPFs to the high beams. I want to use a Toyota fog light switch to control the IPFs. What do I do with the yellow wire?

3. To connect the switch harness to the the Toyota switch, I need to cut off the IPF switch, crimp the wires into disconnects, and connect to the switch, correct? I have red, black, and white wires. Which prong goes with which color?

4. What's the best way to run the wires through the firewall?
Thanks in advance. Wiring is clearly not my forte.
P.S. Here are a couple pages I've been referencing so far for anyone who uses this post in the future with their own wiring needs.
Toyota OEM Fog Light Switch
TTORA - ...ving/Fog Lamps - Faq