In German, when place and time come together, it is time before place. This is exactly the opposite of English where it is always place before time. So, strictly speaking, the above sentence is grammatically incorrect. Still, as word order in German is rather tolerant (not as much as in Russian, but almost) the above sentence is acceptable to many German native speakers, in particular when they are young and/or have only little experience with grammar.

This sentence is correct. You can replace the order of specific parts in the sentence as you like. (Wir warten) (auf Sie) (im Restaurant) (um sieben Uhr) (abends) - Um sieben Uhr abends warten wir im Restaurant auf Sie. - Wir warten abends um sieben Uhr im Restaurant auf Sie. - Wir warten auf Sie abends um sieben Uhr im Restaurant. - Abends um sieben Uhr warten wir im Restaurant auf Sie. Some of them sound better than others, but all in all they are correct :)