Re: golf cart battery installation
Normally, just one fuse is used for the house bank, located as close to the batteries as possible. ABYC calls for within 7 inches.
For many, the MRBF (terminal) fuses will be very convenient. For some, they may not be, due to height restrictions or other reason. There's at least one report of corrosion possibly due to out gassing from flooded batteries.
Note that only three type of fuses are acceptable for direct connection to a house battery bank: the aforementioned MRBF, the ANL (with caveats as reported by MaineSail), and the Class-T fuses which come in larger sizes and are appropriate for, e.g., large inverters. Other fuses do not have a large enough ampere interrupt capacity (AIC)....should be at least 5,000 amps.
Also, only one type of breaker meets this specification: the new Blue Sea Systems series.
You mentioned earlier that you'd connect both wires to the positive end and both to the negative end of the new battery bank. Not sure what you are thinking, but only one connection at each end is required, especially if you're going to use 1/0 or 2/0 cabling. That cable should go to either position 1 or position 2 on your switch...whichever you plan to use all the time.