Yea... the argument over fused or not fused has caused quite a few arguments in boating circles over the years.
In my case, I go with Pascoe. I consider my pumps to be part of the safety system and I don't want an additional point-of-failure so they are not fused.
I look at it as the owners preference.
As for placement of the float, consider this photo that I took after discovering that the solid-state switch on my primary bilge pump had failed.
Both of my pumps are the same size (1500 gph). It isn't easy to see in the photo above, but the back up pumps switch is about 1" above the primary.
My feeling was that if the primary pump (or switch) failed, which it did, I did not want the secondary switch to be so high that the water had a head start on me. One inch above the primary was determined through 'dockside testing' to be plenty of distance between the two without loading me down with extra water.
To be honest, I did not even know the primary pump switch had failed! I was washing out the bilge during spring commissioning and had a garden hose in the bilge flushing out the soap when I realized only one pump was running, and it was the backup! :shock:
After I was done cleaning the bilge, a test light confirmed the old switch was bad.
Since that photo was taken, all three of my bilge pumps now wear WaterWitch 101 solid state switches.