I spent half my time in Japan for several years (3 months there, 3 back home), I absolutely _never_ experienced anything like you describe. Even in areas where I was the only foreigner around. Small children would glance an extra time at me, but everybody else treated me exactly as they did treat others. If I looked like I had some problems people would stop and ask. Service in shops was never a problem. And, as someone else already mentioned, Japan is the only place where I would actually leave my PC on the table in Starbucks while visiting the bathroom. And I'll just repeat again that contrary to your Nr. 2 - I was always offered help if I needed it.

And it just may happen that I'll stay in Japan for my retirement. We'll see. In any case I'll go back as soon as, or if, the pandemic situation is over.