a fuse won't save you from electricution...the body only draws milliamps before you die. You need a GFCI for that. If everything is on a properly sized breaker the system would be protected from shorts and overloads, however if you want to add fusing, try this:
2A slow blow fuse for the pump (so it won't open when the motor starts)
.25 fast acting fuse on the PID (or whatever the required current rating is...check that)
Nothing needed on the SSR...the breaker will take care of that.
Sand Viking Brewery
“Happiness? A good cigar, a good meal, a good cigar and a good woman - or a bad woman; it depends on how much happiness you can handle.” ~George Burns