They bill hourly, but what does that exactly entail? Can I risk ending up with a huge bill at the end of the month, or would I be contained to what I pay for/signed up for?

Regarding photo storage, Immich is pretty close to a perfect clone/replacement for Google Fotos in my opinion.

Looked into selling my old gaming laptop just recently, and it just doesn’t seem like its worth selling them, if they are any older than 5 years, and not top spec. Making a server/node/test machine, might be the best option. Still not comfortable with the laptop battery as ups thing.