Best guess at the moment is that it's a caching issue and you're seeing pages previously sent to other people. In other words get the hell out of steam since if you actually do get to your profile it's likely that'll be cached and sent to other people.

Quite possibly, yes - if you can find the page that gives "your" account information, the language often matches the location.

I should really stop poking around, but this is a fascinatingly bizarre error. Has anyone seen anything like it before?