battery in trunk question

[Crash520]

Hi Guys,
I'm fitting my battery into the trunk, a couple of things I'm persistent on, 1) I prefer to have the starter cable dead unless actually starting the car, I will fit a high current solenoid in the line very close to the battery so as it can also act as an anti-theft, theory being, on start, flip a momentary switch to engage the solenoid and start the car as normal with the key then once started, release switch, then that 1/0 cable is off in case of accident etc. I am then running a large charge cable from the ALT to the battery via a hi current solenoid mounted on a firewall ECU and CDI panel inside the car, this is for emergency shut off again, solenoid controlled via an emergency shut off switch mounted in trunk per race rules. Now my quandary,  power takeoff location to distribution block for EFI.ECU, FANS, and generic power etc, Id rather take it off the battery side of the ALT solenoid on the firewall panel,  per the attached diagram, rather than the starter cable, is it ok to take power from the ALT charge cable that runs directly to the battery or is it better off being a direct ALT to BATTERY cable ????

[Chryco Psycho]

WHY not the battery charge from the alt still conects to the battery when the car is not running , / same circuit