Medical tourism and paying in cash wherever is convenient/inexpensive might also be an option to consider - there are a lot of places that will be cheaper than Europe.
For local media streaming to Chromecast or Apple TV devices, I highly prefer Airflow app[0] over Plex. The experience for playback really is a night and day difference. Scrubbing/seeking is instant and it basically avoids transcoding whenever possible, including when using subtitles.
I don't know what the interest or accessibility of edaravone (Radicava) treatment might be for your dad, but I'd be happy to share my experience with you by email if that is useful - my address is on my HN user page.
From the current research, the best conclusion I've been able to arrive at is we still don't really understand ALS. My opinion is that there may be several distinct motor neuron diseases, each with accompanying cause[s], currently grouped together in what we call ALS. There are notable differences in early vs. later onset ALS, slow vs. rapid disease progression, initial primary symptoms, genetic links vs environmental factors, etc. (I'm not a doctor or professional academic in the field, but I've studied ALS research extensively - a relative was diagnosed and died from it, suddenly, in their early 60s.)
Stephen Hawking is definitely inspiring, with a few unique points - he had an early onset of the disease, slow disease progression, and extensive resources/access to the most advanced care. With mechanical ventilation, caregivers, sheer will, some luck (basically, not contracting a fatal case of pneumonia), tracheotomy and feeding tube, etc - life expectancy with ALS can certainly be extended far beyond what was once thought possible though.
My experience with Lutron's smart switches and blinds has been great. For any new home construction, I would wholeheartedly recommend adding a lot more LED lights than any builder would normally put in, wiring in smart+motorized blinds, and using smart dimmer light switches. The way to avoid fussiness from smart home devices is to choose ones that are controllable in both the classic ways, like with a switch on the wall and/or remote control - and also through an app or by voice with your preferred device from Amazon, Apple, or Google.
With Lutron, beyond the things you mentioned, two more of my unexpectedly favorite features have been:
1) being able to add additional wall switches anywhere and program them to control any set of lights, without any extra electrical wiring (for 3-way or 4-way switches, or controlling multiple lighting circuits with one switch)
2) range-based programming (e.g. automatically turning on lights for rooms from the garage to kitchen when you're arriving home)
Other devices like smart locks, smart garage doors, water leak alarm sensors, and AV equipment have all been useful and generally worked well for me. Some of them have been slightly fussy, but not as a general rule and certainly not to an "unbearable" extent. Overall, they really do make things significantly better, at a surprisingly low cost compared to the rest of home construction.