Thanks for your suggestions so far.
Here are some observations, maybe they inspire further suggestions:
On familiarising myself with the tunes:
I've downloaded the mp3, the code was in the book. For now, I've listened a few times to the songs I wasn't familiar with. For the songs I know, I've picked out the melody from the standard notation and played that on my flute. I'll end up highlighting that melody and then decide on which notes to leave out or change to simplify the fingering. So I do have an idea on how to proceed and add more to my basic vocabulary.
Realistic goal, time it will take to learn the songs:
I regularly go back to music I have been studying and then left to start something else. It is one of my biggest weaknesses: I never really finish something. I work until I know I could play it at an acceptable amateur level. Then I start on something new. When I revisit the older material I find them interesting again, I try different phrasing and sometimes it makes more sense than before.
I suppose I'll hunt for the easiest parts in all ten songs, and then expand on the bars I feel confident with. Even if in the end I can't 'perform' a song, I'll still have gained a lot of insight of patterns etc. I can use to noodle around or improvise.
I estimated that I would need at least 5 years in order to learn all of the arrangements. However, that would mean spending a lot of time on my low G tenor. I do have some other musical projects going on on different instruments.
On learning music by heart:
I often play flute music from memory, though I really shouldn't. Maybe I'm just getting older and I can't memorise as easily anymore. But Telemann's 12 Fantasias, which I have been working on for the last three years, is too challenging to play without the sheet music. I try to learn songs from YouTube tutorials without the sheet music, and it works for as long as I am learning the song. But leave it a month and I'll have forgotten many things, except for very simple arrangements such as the Jurassic Park theme arrangement from the Rock Class 101 tutorial.
I wonder why the selection of songs is presented in that particular order in the book, as they do not appear with supposedly the most difficult song as the last one.