I agree with you, felt like we didn't move on in the plot except second couple which i'm being honest I'm not really into. you can totally skip the whole episode and won't miss anything for ep 7.
The show was really great! I'm a huge fan of Moon Chae-Won and Lee Joon-Gi since both of them are phenomenal actors, especially Moon Chae-Won. It's one of the few shows in which the writer did their jobs till the very last episodes, which isn't a given in most Korean dramas unfortunately. It's not perfect but I really enjoyed watching the series.