Rewiring my Duster, but have a few questions

Hello all.
I have a 70 Duster 340 that I have been customizing for years, power windows, locks, A/C, electric cooling fans and big stereo. I did amp meter bypass, headlight relays and larger altenator wire and it all works fine but its a wiring nightmare so I ripped it all out and am starting over.
I have a new EZ wire harness I am going to install after I make a few changes to it. Fuse panel and relay panel will be located in glove box.
The battery, voltage regulator, solenoid switch and stereo amps will all be in trunk.
Here is a picture of my charging and starting system.
Main Harness.jpg2.jpg My questions are
1 With voltage regulator in trunk are #18 wire large enough
2 Should I use fusible link or breaker for Rad cooling fans
3 I will be using relays for headlights again to take load off switches, is #14 gauge wire good enough for headlights or should I step up to #12

I hope the experts here can have a look at my plan and let me know if I am doing anything wrong or have better suggestions.
Thanks all
Mike