Honeymoon in Seoul/Busan

Heyo, me and my fiancee are planning our honeymoon in October. We already have our flights and stays booked. I'm doing an itinerary for us, so was wondering if I could get some advice on what we could visit or maybe even leave out. We're fairly active travellers, but I'm aware that you can only do so much in the limited time that we have.

Day 1 (Seoul)

• Land in Seoul (flying from Europe)
• Ikseon-dong and Insa-dong (it's near our hotel)

Day 2 (Seoul)

• Hike in Bukhansan National Park
• Hongdae
• Maybe check out Yeouido Hangang Park if we're up for it

Day 3 (Seoul)

• Gyeongbokgung Palace in the morning
• Bukchon Hanok Village
• N Seoul Tower

Day 4 (Busan)

It's gonna be on October 9th, so there's gonna be a national holiday as I'm aware, as well as the Film Festival. Keeping in mind that we have to book train tickets as soon as they're available (30 days before)

• Travel to Busan
• Ahopsan Forest (planning to go by taxi to save time)
• Gwangalli Beach towards the evening

Day 5 (Busan)

• Gamcheon Culture Village in the morning in order to avoid tourists
• Will try to book a Sky Capsule for the evening

Day 6 (Gyeongju)

Afraid this day might be a little packed, but here are the places I'm hoping we can visit

• Travel to Gyeongju
• Bulguksa
• Bunhwangsa Temple and Stone Brick Pagoda
• Gyeongju Gyochon Traditional Village
• Cheomseongdae Pink Muhly
• Wolji Pond and Woljeonggyo Bridge in the evening
• Booked a Hanok stay

Day 7 (Seoul)

• Travel back to Seoul
• Myeongdong Shopping Street
• Cheonggyecheon stream
• Last night in Korea

Day 8 (Seoul)

• No idea honestly, maybe Seongsu-dong 1(il)-ga
• Flight in the evening

How feasible is this? Is there something I overlooked?