I had not figured how to wire it all together... figuring that I would cross that bridge when I got all the parts, depending on what parts I choose to use.

The one thing that does bother me about the whole thing is that I would hardwire the circuit breaker around the battery main switch (directly to the battery), to power the bilge pump no matter what the setting of the battery switch. I'll put a fuse in line, right at the battery, just in case.

Why does this bother me? Well at present, I can "shut down" the entire boat with the battery switch, with the bilge pump, one circuit would remain hot.

So your toggle switch just parallels the float switch. Simple clean installation. And yeah, I was going to do the alarm too.