taomubiji

Thank you for making a detailed outline! but there are still some things that are not right like:
--Neither the Time Raiders movie nor the Conjuring Curse movie are based on Book 1. Time Raiders is loosely based on the series but not based on any particular book.
And if you want some more clarity:
--Tibetan Sea Flower is based on a sequel of the same name. It's the first sequel.
--Tomb of the Sea is based on the sequel "Sand Sea." Tomb of the Sea takes place after Tibetan Sea Flower.
--Reunion: The Sound of Providence Seasons 1 and 2 are based on a sequel of the same name. Reunion takes place after Tomb of the Sea.
--The South Bureau is based on a sidestory novel with the same name. It takes place before The Lost Tomb and The Mystic Nine.

guardian and advance bravely have a similar bromance concept

Where Zhang Qiling went for those 10 years is discussed in the books but is not mentioned in the shows. In the books, Zhang Qiling goes behind the bronze gate again for 10 years.

I voted for Beyond Evil and Love Redemption. Beyond Evil definitely gets better after 4 or so episodes, so it's worth trying again. Love Redemption is also quite great, but I feel like it remains pretty interesting throughout. So, if you don't like the first couple of episodes, you probably won't enjoy the rest of the drama.

Hometown Cha-Cha-Cha is okay and the quality remains the same throughout. So, if you didn't enjoy the first couple of episodes, then you probably aren't going to enjoy the rest either. The other dramas I either never watched or dropped, so I can't help you there

yes, there is a romance storyline but it's not part of the main plot

The author does continue to write about Li Cu but not much. This show is quite different from the book, it can be read here https://merebear474765851.wordpress.com/daomu-biji-vol-10/ (the book is unfinished). The book better explains some things, but still leaves others unanswered

episode 15

I think there is a possibility for an adaptation after Reunion. The author is writing a sequel to the book Reunion is based on. But I don't think it will air in the near future

I liked this more than the original—especially the male lead. Overall it was really good! I gave it 9/10

So, a bittersweet ending?

Zhang Buxun is not the same person as Zhang Rishan who appears in Tomb of the Sea. Zhang Buxun is not in the novels and is an original character to The Lost Tomb 2 and appears again in The Lost Tomb 2: Explore with the Note (same production team). So he isn't connected to the other series. I think the second part is answered in The Lost Tomb 2: Explore with the Note (which I have not finished, so I can't answer it).

For the second paragraph questions, I think this is something we will never know. This part is not well written.

Does this have a sad ending?

I liked it. His character was really good in this

You can watch this as a stand-alone series

so far, the movie just seems like another adaptation of the book. I haven't seen any Chinese fans or media referring to it as a sequel

I also found it very boring at first, it picks up around episodes 8/9 tho. I'm at episode 18 and I'm so glad I didn't drop it

Yep! There's not a whole lot from The Lost Tomb that carries over.

But just to clear up one possible source of confusion. Wu Xie got the snake brow copper fish artifact from a tomb in The Lost Tomb. This will come up in the first episode of The Lost Tomb 2

this was better than i expected, but the plot is a bit all over the place. A 7.2 rating is relatively low, i think this show is similar to other shows around the 7.4-7.6 rating on mdl

You don't have to watch the lost tomb and the lost tomb 2 first. Many people start with Ultimate Note because it does a pretty good job of summarizing what happened in the previous adaptations. Someone even wrote an article about it: https://kisskh.at/article/yw-done-devitto-done-watching-ultimate-note-as-a-stand-alone-drama (contains spoilers)

However, if you want a better understanding of the characters, then the order is:
1. The Lost Tomb (https://kisskh.at/11050-the-lost-tomb)
2. The Lost Tomb 2 (https://kisskh.at/28695-the-lost-tomb-2)
3. The Lost Tomb 2: Explore with the Note [aka The Lost Tomb 2.5] (https://kisskh.at/64387-heavenly-palace-on-the-clouds)
4. Ultimate Note (here)
—Time Gap of 6 years—
5. [unaired] Tibetan Sea Flower (https://kisskh.at/56837-can-hai-hua)
6. Tomb of the Sea (https://kisskh.at/29686-sand-sea)
—Time Gap of an unknown amount of time. Should be around several years—
7. Reunion (https://kisskh.at/30581-the-lost-tomb-3)
8. Reunion 2 (https://kisskh.at/70645-reunion-the-sound-of-the-providence-season-2).

I agree, I'm glad they took it out