Short answer: With all your stuff I would relay em all directly to the alt not to the battery. This lets your high powered alt power all the extra high powered draws & keeps the ammeter honest & keeps the rest of the electrical system out of the picture except for the minor current needed to trigger the relays. I would definitely still do Nacho's parallel bypass on the 2 main in/out wires at/thru the bulkhead. EDIT The Madd bypass is excellent IF you are OK with giving up your ammeter function. I'm old school & I like it (plus an added voltmeter to switched 12V)