There are many malls, shops in this area, etc. It depends on the season. There was a typhoon when we visit so most shops close early due to transport issue. It was tough to even get a taxi during such weather. Otherwise, most malls closes by 10pm. For specfic malls, suggest you google directly as we visit during the day as we wanted to see the market after the cultural village. Check before you head out is my advice, Visit a specific area rather than just one tourist spot. This allows you to see more within a shorter period. Knowing what you like to buy will help too cos different areas sell different items. Do visit the local busan market...local handicrafts etc. This is unique. Have fun!

Not too sure but.would be advisable not to go after 6.oo pm

If I remember correctly, some (but not all) are already operating around lunch time.

It is better to make your own tour, you have enough time to linger to certain place if you want. Transportation in Busan is more convenient than Seoul. If you happen to stay at Haeundae area, it is easier to take public transportation. Do not forget to visit Haedong Yonggunsa Temple

I would suggest u directly message Olive & young store for more directions details, I don't think most of us would remember which shop available there or around the area unless they bought from the store from said store before.

The food stores are open till late but shopping area closes around 11pm

Unfortunately, I haven't been to the film festival however I have been to BIFF square as well as the Jagalchi Fish Market which are within walking distance of each other. When you visit Busan I would highly recommend in order of priority: Gamcheon Culture Village, Jagalchi Fish Market, Busan Tower, and BIFF square (if you have time). Great Travels! or visit me at Buftravels!