I used wiring similar to what tinkicker described, 150A fuses at the batteries, and never any problems. Years later, I get a dc clamp on amp meter, and decide to measure my starter current on the 5416. I measured 30 amps( 360 watts ), which makes sense giving the size of the starter motor. Definitely go big on starter wiring, sometimes my starter battery needed all the help it could get!
Venting is nice to prevent explosions. Not quite as important, but heat build up during rapid charging is a concern for the health of the battery. Batteries are in engine compartments often, so i think abyc is with ok as long as there is a ventilation blower for the compartment?