Continuing:
Lots of things come back and bite you because you don't realize what you need or why you need it. Take for example wire: There is copper, solid and various stranding varieties and colors. You might need 6", but need to buy 100' for $20 or so, so that's $60 for 3 colors. That's just for ground, hot and neutral. Now let's say you use 3 different colors for the NC and NO and C circuits of the switch. Later, when you start to troubleshoot, it would be so much easier than if the entire circuit was wired in only yellow wire. Yep, I sad to troubleshoot such a mess.
When I did control panel wiring, I used 18 AWG with a smaller number of strands like 7, so they were less flexible. Solid wire doesn't work well with crimp connectors.
IDEC is my favorite relay manufacturer because of how clearly and where the wiring diagram is. They are available with "check buttons" (allows mechanical activation) and LED's (Coil energized). These can prove invaluable when troubleshooting too. Sockets/connectors can be useful,but are SOMETIMES a source of reliability issues.
A connector in this case could offer "strain relief" capabilities and the ability to switch floats easily, but there would be a tendency to make the floats not directly interchangeable to avoid putting the system together wrong. I also tended to use a larger connector with VERY easily replaced pins, thus these were reuseable for other projects. Cord diameters were accomodated with different shells.
My construction technique comes from how telephones are usually wired in a large office. Each room gets its own terminal and risers and laterals get their own terminals. You then cross-connect within the wiring closet.
I digress: In a home, what I would probably do which is not a standard practice. In a home there may be few lines, a burgler alarm RJ31z jack, and Ethernet with lots of locations, I'd probably use CAT5E or CAT6 cables to corresponding RJ45 jacks at a central point.
I'd create one panel with 4 lines bussed which would distribute the lines. So you would have, room jacks(2), ethernet switch and a panel of 4 bussed lines. I would do any line transformations in clearly marked patch cables.
One of the typical arrangements is FAX, DSL, Business, Home and alarm. Alarm could be a PERS (Personal Emergency Response) or Intrusion or a combination. A PERS panel might be installed in a bedroom. So, things can get messy real fast. While the house I live in was wired some 50 years ago and 90% quad wiring, non-home runs and 4-prong and modular connections in the same locations I had to make some changes such that I have "A pristine DSL" install per the telco technician. Tracking down static when there are 12 or more paralleled connections can be tough. I had water in a cable and cobwebs in a surface mount jack(same run) after a flood and rain. The jacket took months to dry out once identified. I still don't like about 6 wires on the original stud, but at least I have a disconnect point. Which phone is off the hook is another problem.
Anyway back to wiring. The DIN rail construction technique combined with what I might call telco wiring methods works very well. The DIN rail allows easy changes and the terminals are about $2.00 each. In this technique, each input/output would get its own set of terminals. Even with what you have, you end up creating terminals very quickly: Power in, power out, bottom float, top float, alarm silence, battery, arm, disarm, (run pump manually), (float status). the last two I just added for fun as they could be additions. I might try to accomodate these changes at a later date.
You get the idea as to how simple things can become very easy to troubleshoot, modular and reuseable. One or many plays a role too.
Here is a sample:
DIN Rail Terminal Blocks