1. you can but by running your battery all the way down, then charging it back up, you will kill it.
2. the plug is an field wire to make it charge, voltage out to your regulator and one to your charge light, IIRC.
3. you need the battery to provide power for spark. it does this on ALL engines. Your alternator keeps the battery full and helps in high amp draw situations.
4.GET THE RIGHT UNIT.
