Anecdotally, I don’t find point 1 to be necessary at all. Points 2 and 3 are vital, however. As long as I cut work off at the end of the day, I’m fine.
I don't have any problem disconnecting from work, but it probably helps that I have a different computer for work that goes in a drawer at the end of the day.
I do follow points 2 and 3 though and I think those are essential.
Me, my work-desk and pc-gaming-desk are one and the same, but I have different keyboards (PC vs Mac) for the one or the other. It's not ideal though, I'd love to have a dedicated office space and time with e.g. an own kitchenette so I don't have to dart in and out of the shared space of the kitchen multiple times a day.
I'd say that's my main issue; my workspace is separate, but everything else isn't. And it disrupts my family members' days as well. I should go to the office more often.
E.g. there are times that I do break the rule (very rarely) and get on my work computer (e.g. download work documents for tax prep), and part of me feels like I'm back at work.
If you've not tried it before, it may be hard to relate or recognize the difference.
Work to me is like going to the bathroom. I go, do my business, then leave and it's back to my normal day. With WFH, that's even more the case.