I'm not really "down with the kids", but I would think most people in their twenties and thirties and older would definitely understand "bender" to mean a homosexual, and "on a bender" to mean "out getting drunk" (though this isn't a derogatory term in any particular sense). I don't think I've ever used the word "bender" to mean "thing that bends", but perhaps that's just because of the other meaning of the term here.

I don't think "box" is understood at all in the UK to mean what it does in US slang, though we do use the word in the context of cricket to mean something quite specific!