Dr Dave, I believe the circuit breaker will take the place of a fuse. I prefer to reset a breaker instead of replacing a fuse. Like the small gel cell battery for the brakes.
catskinner, I assume my 200A alternator is enough to use the dump trailer. Of course, I could be wrong. You know what happens when you assume. About the isolator. I thought the solenoid takes care of that. There I go assuming again.
Are you sure you have a 200A alternator? If that is the case, then your system will bnot be overloaded. You are correct about the solenoid if you delete the battery. Let us know how everything works, I'm always interested on how other people figure out solutions to problems.