Hello ! I'm French and doing this lesson in reverse to test me. So, "jusqu'à chez nous" is a very ugly phrase in French. We can say it, but only in oral and in general Frenchs who say this, don't speak a very good language... hope i've help.
No. As a French learning english, i can tell you that the french pronounciation of the S is different. Pluriel in the end of a word is never pronounced. Il marche and ils marchent are pronounced the same. Hope i've help.