Fellow puzzlers!

On my vacation to Norway last summer, I’ve gone on several hikes through the mountains. While the views were absolutely amazing, the hikes also left my with a mystery… On, if I recall correctly, my third hike, I found a note in a pretty well-hidden cave. I left the note there, since it was obviously meant for someone, but I took a picture. I’m not able to find the picture on my camera roll anymore, but luckily I still have the transcript I made when I got home:

Hei, Rob, would our quiz help Raj in each situation? Say firm each hyphen, flag and GUV. 
   -- Succubi Queen

It was dated the 30th of june.

One week later, while hiking on a path close to the one where I found that note, I found another note in a similar cave! While the style is completely different, I can’t shake the feeling that they’re related somehow… The transcript is below:

A new, good opera, on the eleventh left capital house owner. It leaves only created huts, or all nitpickingly killed, eaten elk. No drama, in all, in every red raging automobiles. As per a new incident, for our races, maybe unlucky lasers used unjam low, uh, I mean, all cars, how odd.

On the back, there was a note saying that it was “Written at midnight, under the highest sun.”

I’ve been trying to figure out the meaning of these notes, but have not been successful as of yet. Since you guys seem to have quite a bit of puzzling/cryptographic experience, I was hoping you could help me out!

NOTE: The story is fictional. Whether or not it is needed to solve the puzzle, is revealed in the minor hint below. The encryption consists of multiple layers, and partial answers are encouraged.

Minor hint:

Most of the story is just flavour text. The dates serve as a bit of a hint on how to solve it – more on this later. The fact that it is set in Norway is not really needed for the puzzle, though it gives a bit of a confirmation of Jasen’s observation about the arctic circle being relevant.

Hint:

It seems that one of the letters was encrypted using instructions from the other… If we can figure out what the first and last letters are respectively, we shouldn’t be spending any time trying to get anything meaningful out of the letter which was written later.