I agree with pretty much all you said and I think it sums up remote work relatively well. I'd just add that off-home workspaces (coffee shop/co-work/libraries/etc) are also a very viable option.
Personally I can't work at home, even if I had a dedicated office, something to do with a clear mental barrier I put up a long time ago (I'm actually grateful for it). As you mentioned, working home can really mess you up if you're not careful. Having a very diminished commute to a workplace that's not your home can help you tremendously if you have the same problem as I have. Not saying you can't work at home, just saying that there are alternatives.
One more thing, about being always available, I think one should be careful about it, otherwise the only thing you'll be doing is replying to slack/email/chat messages and not being able to get any work done. When in doubt, iterate and learn. :)