You can do both. Sell a license and sell cloud storage.
The price depends on the market. Some people won’t pay out of principle, and some might even think it’s too cheap if you provide enough value.
The only way to truly know is to actually build it and sell it.
Best of luck!
I'll add that sometimes the self-hosted version does something that the "official, paid"[1] version doesn't, or at the very least allows you to try to hack it together.
A problem with commercial offerings is that their idea of completed product is different than yours, and depending on the feature there's not enough $$$ incentive to pursue it. This is the major problem with Google, because search is such a ocean of income, that no other project will ever stand up to it.
[1] I say official because quite a few of self hosted versions are clones of some paid product.
Is there a typo on the HDD prices? Looks super expensive. With that amount you could have 48TB of NVME drives (assuming you have a controller for that many sticks, but you probably could buy one with the leftover from the sticks)
In general you shouldn't spend more on newer/larger capacity HDDs unless you absolutely need that much storage per slot (that is, you are space constrained), as the prices invariably go down in less than an year. Smaller drives with 12~16TB are a much better TB/$. Check diskprices.com to see current trends.
If you care about speed, relying on HDDs for that is a bad proposition. You are better served by a SSD cache in front of the HDDs. In case of SSD failure, it's much cheaper/faster to replace that SSD than to rebuild your strained RAID.
As for CPU performance, pretty much any newer Intel QuickSync will handle your needs. If money isn't an issue, I'd rather go with Intel NUC 12th gen or newer. I have one and it handles anything I throw at it, including the most demanding 4k transcoding. The NUC and a 4-disk Synology uses less than 50w with the disks being used.
iOS is very picky with background jobs. Not many apps have background upload for that reason. It seems Immich managed to make it work, but I haven't tested it myself. Naturally, Photos app works perfectly with iCloud...
Android is more lax and so many more apps support this feature.
As an experienced software developer, I can confidently say that no amount of technology will fix a bad user workflow. Your best plan of action is to sit down with your mother and try to come up with a consistent workflow she is happy with. If she doesn't know or can't come up with one, find what is the industry standard (which seems to be year-month-date folders? I'm not a photographer), or maybe ask an experienced photographer friend. Remember you can adjust the workflow later, but it's important to have something stable while she is learning how she really likes to work.
Storing the photos in a NAS is a good choice. For the slowness, I suppose she would need to keep the most recent photos on her main computer/laptop, then move/sync to the NAS once editing is done? I don't see why one would need to edit old photos every day, so keeping only the most recent/active work on the computer seems smart.
adobe Lightroom performs bad with network drives
Most software perform worse with network drives because the host OS can't optimize as much as a local drive, specially so with random access like editing software do (contrast to copying/streaming a file, which is sequential). If performance is an issue, the only real solution is to copy files locally then sync back to the NAS. You can diminish the latency of network drives by having a SSD on the NAS, and a better link between them. Gigabit is a good start, but I'd go with 10Gbit because although the files are 70MB in size, lightroom is probably fetching several photos at the same time, and it will easily saturate your Gigabit link.
Good luck!
If scanning manually doesn’t work, then there’s a larger issue here. Faulty HD perhaps?
Otherwise, this happens to me when Plex is using a folder that is mounted on a file system with no inotify support, such as network shares. You mention you have SMB, but it’s not clear if Plex is using the folder over network or not.
If you have the skills, jellyfin!
It all boils down to what you want to use it with. 16GB is plenty for what you are describing right now, plus more in the future if you keep your installation tidy.
Would I limit myself with a max 16gb system? Probably not, unless I was certain my usage for that device is fixed or another external factor (e.g., I got a huge deal on that device)
Also keep in mind that N95/N100 are more power efficient than a Ryzen.
I’m not sure I understand the multiple web servers issue. If you forward your wan port to a web server in your network, only that one web server will be exposed. Unless you are mistakenly forwarding the other ports (eg 1234) as well?
In any case the way to go is reverse proxy. Mine have both subdomains and subpath, and they work perfectly together
Fastmail and nextdns. I'm still paying for iCloud, but I intend to move everything to my local server.
I go on and off streaming services: Disney, Hulu, Netflix, HBO.
Amazon Prime, which includes a bunch of goodies.
Kindle Unlimited. I usually wait for promotions since there isn't a ton of material I like that I haven't read yet. Also I'm rather busy lately.
Any recent PC will do. Naturally, if you plan on playing games on it (moonlight and sunshine) you should size appropriately, and I’d recommend not to mix your NAS with a gaming PC since games and accessory can crash your server.
Without gaming, any 8th generation Intel or newer with iGPU should handle most transcoding needs. It’s more than capable of handling all the services you mentioned (again, not considering gaming)
I’d look into mobile class cpu so it’s lighter on energy consumption.
Static site generators are a dime a dozen. The simplest being just typing HTML into a folder and publishing to a cheap static hosting website (also a dime a dozen).
Hugo and Gatsby are popular SSG, and you can find more in https://staticsitegenerators.net/ and https://jamstack.org/generators/