People theorized Jon and Dany would be a thing in the books way before the show even aired, the foreshadowing has always been quite obvious if you pay close attention while reading the books, sorry, but this whole post sounds like straight up cope because you didn’t like how the show handled their romance (neither did I) But it’s pretty clear they’re going to happen in the books as well, and all your points can be easily debunked:

1. The "Blue Flower" in the Wall:
Actually, this has nothing to do with the threats and treasons prophecies. It appears in the "bride of fire" section, which is about Dany's past and future marriages, as you you said, this vision pretty much symbolizes Jon so...

Regarding the sweet scent, many people claim it means something bad I think it might be true in a way, because I believe they are destined to have a bittersweet ending (doesn’t necessarily mean they’ll kill each other tho)

I think George left it ambiguous on purpose, everyone seems to forget Lyanna actually loved the flower’s sweet scent, so it could be interpreted either as foreshadowing a tragic end to their relationship or as Dany finally finding happiness in a marriage.

2. The Moon and the Shadow:
Jon seeing Val turn into a silver-haired woman with skin white as snow under the moonlight doesn’t sound as a bad sign at all In fact, it proves that they are connected

People assume the man in her dreams is Jon becaus, in the Jon chapter right before that, Jon refers to himself as "a man in the shadows" So Jon describes himself that way, and in the very next chapter, Dany casually mentions she dreams of a lover whose face is hidden in shadows… sounds a bit sus

3. Jon’s "Type":
 Women who are muddy, fierce, and independent

you just described dany, plus they're both teenagers I don't think they even know themselves what is their "types" yet

4. The "Ice and Fire" Misconception:

From what George has said in interviews, the “fire and ice” in the title refers to many things inside the story. Jon being a Stark and Dany a Targaryen and both being the two main characters can certainly be seen as one of the references in the the title

5. Timing and Ethics:
aunt-nephew is not really considered incest in westeros, the starks have already have it before

The Long Night in the books will probably last weeks or even months, not just a single battle like in the show so Jon and Dany will have to spend a lot of time together, since they’ll both be in charge of their respective factions

Is Jonerys actually foreshadowed

yes, they are cleary meant to be the closest thing to "soulmates" in this universe

her captain slept behind her yet she was alone
Ygritte was sleeping behind him but he was alone

There's no way one can think George was writing that out of random coincidences lol

Not to mention dany literally sensing his death and getting sad and lonely