There isn't really a size limit. Of course, feet between 34 and 46 fit the machine very well. You need to position your foot well at the back of the machine. No shoes, preferably socks or bare feet. The size cannot be adjusted.

of course i can't answer you exactly to the degree... but it heats and is therefore a foot warmer too🙂

It is comfortable for european size 43 and still has space left for bigger feet. I'd say 46 should be possible to fit inside but you might not exactly get your toes massaged.

Well if the return policy says no, then no xD If you buy the warranty upgrade to premium express service for two years, it's only an upgrade for the existing warranty, not additional 2 years. But you can buy additonal 1 (max 3yrs) or 3 (max 5 yrs warranty)