This might trigger your OCD, a small part of a more simple flow 
..
Please excuse the dust 
Urm, yes. I prefer mine to look like this:
Indeed, that is one of my more messy ones as it is from my dev instance. However, it does show how I use Link nodes to keep everything both neater and comprehensible. Also shows the use of comment nodes so that it is easier to remember what is going on 12m down the line.
It probably shows how my brain works I do agree with note nodes though, even a week later I forget what does what. I do intend to completely update my network, move all if it a cupboard and replace my ageing router(Draytek2600VG last sw update 2006...) with separate pfSense, unifi AP pro and a Draytek 130 modem.
Ah, a Draytek was the first decent high-throughput router I owned - 7800N? Eventually the WiFi on it died. That is reasonably common on combined routers which is one reason I don't buy them any more - that and the fact that nearly all of them are overpriced rubbish.
I've occasionally been tempted to run a separate firewall but then I got a Ubiquiti EdgeRouter Lite and it is so good that I've not found any need. I do have a separate residential gateway/modem that BT provide but I have to have that. It connects to the router.
Good choice 
Originally I had the UniFi LR (not the pro) but upgraded. It is so good that I don't have to run a mesh - though with the Ubiquiti's I could of course.
I don't want to lead this thread to far of topic, put I plan to 'play' with servers(don't tell the wife 
) and VLAN's hence pfSense. I experiment on my laptop with Virtualbox running pfSense etc and XCP-NG virtualized within vmware which, surprisingly does work.
Back to Node-red, what does your system(s) do ?
Sounds good. I'm sure the wife will understand 
It takes data from various sensors, remote switches, movement sensors, door sensors, the smart heating controller (Drayton Wiser) and the weather. Sensor and switch data is normalised and output to MQTT. Firstly in raw format, then translated by NR to more useful topic structures such as temperature by location, etc.
I typically track temperature, humidity & pressure with weather to monitor our old Victorian house and the weather to try and predict when we need to dehumidify or tweak the heating.
Light is tracked to control some lighting automatically.
Movement, door and sound is used to monitor house occupancy - for security mainly though also useful when the kids are around but my wife and I are not 
Freezer door sensor checks for when my daughter has left the freezer open.
The wireless door-bell is monitored - well because I can! Actually, it was useful when my office was in the loft as I didn't always hear the ringer.
Lots of this data is passed to Telegram as well as MQTT so that I can monitor and control things remotely. I have a few different channels - each with a different level of chatter. From minimal that the family can use through to noisy that tells me lots about what is going on.
All data is also written to InfluxDB for historic monitoring. Interesting to see the relationships between the atmospheric measures internally and externally. System monitoring data is also sent to InfluxDB for monitoring as well (using Telegraf not Node-RED).
Light switches, heating details, sensor data and sensor platform data (online, etc) is also delivered to a home dashboard that uses uibuilder and custom Vue/Bootstrap code. That is very much a work in progress but is being used regularly to control lighting along side physical wireless controllers.
Not to forget that Node-RED controls automated lighting as well.
I think that is most of it. The picture I shared is a dev copy of part of a flow from my live system that grabs data from MQTT and from the heating system and sends it to the custom dashboard.
