Agreed - I've been in a fully remote team collaborating pretty intensively with other team members, screen sharing and pair programming over Skype/Screenhero/TeamViewer or whatever the designated tool is. Asking questions through irc/Slack means that communication is a little more asynchronous than face to face but we'd use short Skype sessions when we needed to be a little more involved. Increased autonomy can be part of it but it really depends on your workplace.
I mentally filter out those ads - they're almost always looking for US-based, sometimes even only their city. Others like remote "for the right candidate" give the impression that they'll take on remote workers only as a last resort, which seems unlikely to work out if that's their mindset. The best results tend to mention "remote-first" or "international" - to me this says they have a culture of remote work, properly understand where it does and doesn't work and know how to get around or mitigate its limitations. The most annoying for keyword filtering are, of course, "no remote".
Without addressing any of your other points (being outside the US, I have no knowledge in this area), it's interesting to note that at least one of the co-founders of ModCloth has a number of regrets about the opening of the SV office, and considers that staying in Pittsburgh may have been the better option:
Another data point for Australia - I recently applied for a job with a description that included quite a large range of technologies, all of which I happened to know reasonably well. Was contacted back only to find out that not only was it not a single position, but it wasn't even for the one company. The recruiters had just pulled together all of the requirements from multiple jobs and put them all in one ad, which would have been fine if they'd made that obvious. Maybe to save advertising costs? Whatever the reason, it didn't leave a good impression.
It really depends on how loose your classification of "diamond" is and how large you want. Cubic zirconia is quite popular with hobbyist and some professional faceters and is quite readily available in a range of colours (try searching for cubic zirconia rough) but it's more difficult to manufacture the larger you get. Moissanite is much closer to natural diamond in both hardness and refractive index but it still seems to be fairly inexpensive uncut. Not too familiar with other diamond synthetics but the range seems to be growing.
Several years' experience working remotely, focused on the back end but often needing to wear the generalist's hat. I'm interested in open source and getting away from pouring code into the black box of enterprise/government. Currently enjoying learning FP concepts, I try to keep up with continuous education.