1. A breaker is not a replacement for a Fuse, a breaker can fail, especially those cheap Chinese ones, his breaker is installed outside the pack which leaves a huge amount of "earth cable" that could short and cause a serious problem.
I disagree that a quality breaker can't replace a fuse. Otherwise our homes would have fuses. The line-side wire to the battery should still be within 7 inches. Midnite/Carling Tech is an example (and is what I'm using, in my parts list in my sig).