wiring question; standalone harness LS1

[ACII]

Hy all

i am almost dones with the stripping of the original harness..
just need to re-route and hook up the relays and foose box.

I am just a bit confused about these three plugs ....as u can see on the pics..

First / second pics --> pls let me know for what i need the plugs ?

third pic --> The plug with the big wire goes to the starter....where do i need to hook up this wire ??

Thanks for ur help

Cu
Achim