I have 30+ zwave devices on my homeassistant and some years experience going back to the X10 and insteon days and here's my comments on the article and other folks comments:
1) TLDR does not like the effort required for hard wiring. Solution I used? Never hard wire end devices. Makes it easy to take it all with me if I move. Pairing is insanely simple and done in infinite comfort in my office chair not on top of a ladder or whatever nonsense. Then once it all works I plug it in the official place. I hated replacing my hardwired insteon switches. Obviously wall switches have to be built in, but why would I have to climb a rickety ladder with a laptop per the linked article to access a wall switch? And I've had ridiculous good results with RF switches and with automation based on presence and timers I don't "need" wall switches nearly as often. There's no point in rewiring a wall switch for my driveway and side door lights if the lights are now near 100% controlled by elevation of sun and position of garage door and some software timers. Honestly I'm not entirely sure where my physical garage light switch is...
2) Never had a problem with healing
3) Yes I too ran into scaling problems where I have a "large" number of zooz Zen15 inline switches and they work great but the out of the box homeassistant config had them spamming the current voltage and current ... current like every second. Which looks nice when you're demoing one device. Not cool if you have 20 of them spamming the unholy hell out of homeassistant. There are config options to fix that and suddenly my network works better including healing.
You uh, do know you can have multiple zwave systems? I mean zwave the protocol only supports 254-ish devices off a stick, but another stick is like $15? And to some extent with MQTT and some virtualization you can have "infinite" HA servers running? I was amused with the idea of running a separate HA instance for every ROOM in my house on docker. Its not hard to pass usb access thru docker and the sticks work fine. I would imagine if I ran long USB extension cords and multiple zwave sticks each with only like 10 devices that network thruput and healing times would be AWESOME. But I'm lazy to set this up and I only have like 30+ devices so...
4) See my virtualization idea in #3. If an aeotech zwave stick failed (note, never happened to me nor heard of it happening to anyone) then I'd cry some if I had the protocol limited 254 devices to re-pair, but with only 10 in a room or whatever, eh who cares something to do for a half hour while listening to a podcast or something.
5) Hate to repeat myself see virtualization idea in #3. Again, if my entire system died I'd be sorely inconvenienced, but if my living room virtualized dockerized server died I'd only be out my automatic fish tank lights, my automatic presence detected and temp controlled ceiling fan, and some area lighting effects based on roku and other TV device status.
6) Seriously dude I lived thru Insteon AC line caps blowing every year or two, you have no idea how good you have it with zwave. But see answer to #1 again. Have a zooz zen15 ready in backup and its like 5 minutes work to swap them out.
7) I have not had a dead node problem. Interference related? Only when the microwave oven is on? Honestly I donno. It sounds anecdotal along lines of "Don't use Verizon worldwide because my local tower sux"
8) Confused what short lifespan Chinese outdoor christmas lights have to do with automation. Like if your christmas lights burn out too much it doesn't matter if you don't control them, or timer them, or zwave them.
9) Yeah well CLIs are user friendly they're just a bit selective about who they're friends with. General public maybe not, HN type people will be fine.
10) What price safety, convenience, security? So the "light switch" for my basement stairs is the door, making it impossible to stumble down the steps in the dark, isn't that worth something? Building code requires a light over my entrance door which is practically never used, but now my icy steps in the winter are at least very well lit.
I think the biggest problem OP will have with his esoteric wifi light system is theres maybe 1000x as many casual zwave users and eyes on zwave hardware. Bug strikes down zwave then HA development goes in crisis repair mode with excellent support on the forums. The one install in his state of this guy's wifi thingie goes down, well... reinstall zwave or be very very patient?
People who hate the upgrade process on home assistant: Dockerized HA and tar or whatever snapshot strategy you want. Life's a lot easier than "misterhouse" back around 2000.