What about tracks 10 and 11? Did the video mention those?
Tracks 8 and 9 seem interesting to me. The name of track 9 literally mentions Jizo protects who protects the spirits of dead children and that all ties up with Ebisu, that's pretty obvious but I don't really see how that might be applied to Renko or Maribel. But, researching more into the topic, Jizo is also seen as a deity that protects travellers on roads and considering the name of track 8 literally has road in it, it's safe to assume they're connected in a way.
Considering all the Tanabata references, it wouldn't be too much of a stretch too see a parallel between Renko and Maribel with Orihime and Hikoboshi. ZUN might be too much of a coward to have them get together but he can't hide the romantic tensions between the two.
There is rather to point out with respect and/or praise out the courageous and persevarant justice and rightfulness of ZUN(Jun'ya Ota)to not cave
AND DODGE
"odd (and at odds) kind(s)of romanticism(s) and romance(s) " under pressure & pressurers, influence & influencers, naivety & naive-makers and so on...
Renko's and Marybel's focuses are certainly "reflections of and from Japan-ism, Far-Eastern-ism, Mysterious Boundarirs and Crossings M "Native(Renko), Foreigner(Marybel),International (Both) Japanism and Far-Easternism "...
More in person they are"Quite best close young and, especially Marybel, Partly-Reckless(likely around 24-5 during the middle or later part of University Ph.Doctorates or Masters) Friends, Researchers-Associates,Thinker(mostly-Renko)-Dreamer(mostly-Marybel) INVESTIGATORS-EXPLORERS DUO OF CLUB MEMBERS "; alongside, if I am clear and of help enough , any inklings in-out Gensokyo and then "the other Other-Realms(Lands) and Other-Boundaries(Crossing or No-Crossing Passages)", themore or less meant, remembered, hinted or the like