Charging system and other wiring change help needed

Ok, A few questions as I am starting to do the wiring.
First, is for 67dart273, I already have a Flaming River Master disconnect that Ive had for well over a year and cant send back so I would hate to have to change but I would consider it. Let me ask this question and please understand I am not arguing but trying to understand, What is the problem with having current back to alt as long as the switch shuts the car down(per NHRA)? Is it that if the car should be involved in an accident that a short in that wire could cause fire? How does that differ from a factory original wiring? Again please understand Im not arguing but trying to understand your concerns. I have not seen a wiring diagram that would include a 4 post disconnect and maybe if I did I would understand the difference. Also another issue I have is I have already put a hole/grommet in the cars body for the rod operating the master disconnect, so does a 4 post switch work with a push in rod that I could mount the same as my current switch. And what part # would i order? (I use Summit Racing)

Now with the system I may be forced to use because of where I am invested into(lol) I need to run a wire from the alt to the "ford solenoid" which I have gone with a continuous duty solenoid, is 10 gauge heavy enough? Also should that wire have either a fusible link or fuse in it. I bought some circuit breakers as well would they work better?
Now the wire I would need to run from the Continuous duty solenoid to the starter be 2 gauge?
Im hoping to be able to move the factory starter relay to under the dash. That will require a 2 gauge wire that comes off the master disconnect and go directly to the main stud on the relay. Also on that lug will be the system power wire which since I am dong the MAD update should be the wire that connects both sides of that circuit that was cut and spliced together eliminating the ammeter? What gauge should that be?
The MAD change shows the battery wire from the alt going to that relay stud but with the change i am making with the battery to trunk and master disconnect/solenoid in trunk I plan on that circuit going back to solenoid as I mentioned above.
Im looking forward to any comments or other suggestions.
Thanks in advance for your help. I hope to turn a switch and start this engine in the next 2 weeks so these issues need to be resolved.
Thanks Rod