Given a travel related situation, and given a specific question about the situation, summarize the question into a title

I will be travelling to Hong Kong in a few months' time. I hold dual nationality and neither of my nationalities requires a visa to enter Hong Kong. During my trip, I will travel to Korea for a few days, before returning to Hong Kong to fly home.

Will I require a visa as I will have multiple entries within 3 months of first arriving in Hong Kong, or does visa-free entry allow me to come and go (as a tourist), effectively, as I please?

I'm guessing that using my two passports would be something they would spot instantly and lead to further questions?

Hong Kong: Visa for Multiple Entries?

When I came to Chile, I originally thought I would only be here for 1 month, so that's what I put on my tourist card.

However, now there's a good chance I'm going to stay the full 90 days that my tourist visa allows, and I might even want to extend my visa after that.

Can I wait until the 2.5 month mark to extend my visa, or do I need to extend it 2 weeks before my "declared" trip ends (i.e., within the next 2 weeks)?

Extend my tourist visa toward the end of my "declared" trip or wait until closer to the visa expiration?

I am planning to book an early morning flight from Reykjavik to Berlin via Wow air, its departure time is 6:10 am.

How easy it is to reach Keflavik airport early, is it easy to get airport commute so early in morning?

I can see all Wow air Europe flights depart almost at similar times, so airport will be crowded, any idea at what should one plan to reach airport?

Edit:

Correct above, its Keflavik airport not Reykjavik but its the main airport for International flights.

Update:

I booked Grayline pickup for 3am and it dropped me at airport by 3:50am. I had no problems and reached the boarding area well in time and even submitted my tax refund form.
Catching early morning flight in Reykjavik