Harmen

Subjective, yes. I'm familiar with Shaughnessy's and Pankenier's hypotheses about 1), but I would like to read up on 2), which is new to me - do you have sources for me? Be that as it may, we still have a Chinese text that is worthy of being translated, regardless of all the translations that are already outthere. Considering the many developments in the field of sinology, etymology and linguistics the matter of accuracy is still relevant, as far as I'm concerned. What is concidered 'accurate' is a never ending process.

How would you define 'accuracy'? What do you consider 'accurate'? Wilhelm's Third Book is a translation of parts from the Ten Wings, accompanied by his own explanation of that text. The translation in itself is okay, Wilhelm's commentary might steer you in certain direction that does not necessarily match your own understanding. I would advise to read the text on its own, which goes for the whole Yijing as far as I'm concerned.

https://www.yjcn.nl/wp/the-oldest-source-for-the-coin-method/

The latest podcast that I made with Johannes Bloemsma for our Casting Changes podcast deals with this topic:

--> Going back to the source: the manuscripts of Richard Wilhelm (1) – 易學 (yjcn.nl)

You got the directions wrong. South is on the top, North below, East to the left and West to the right, as is custom with Chinese maps.

The gate says 太清宫, there are (at least) two Daoist temples with this name. One is the Supreme Clarity Temple in Shenyang: Supreme Clarity Temple (Taiqinggong) , Shenyang - FYSK: Daoist Culture Centre - Database (daoinfo.org) The other is the (Laoshan) Qing Gong Temple in Qingdao. As Google Maps shows far more pictures of the latter location I suspect your picture is also from this place. But the text in the footer is unreadable because the image is too small so I am not entirely sure. I have not been able to find other photos of this specific gate.

Because according to legend the Yellow River brought forth the Hetu on the back of a longma 龍馬. See 河图洛书 - 维基百科，自由的百科全书 (wikipedia.org) The Hetu and Luoshu are only mentioned in commentaries though, and don't seem to be connected to the Zhouyi, the core of the Yijing. Scholars are also not certain if early references to these charts refer to the pictures that we know today. Originally the Hetu and Luoshu might have been totally different objects/shapes/principles.

The corresponding YouTube channel can be found here: Casting Changes - YouTube.

Exciting news! Johannes Bloemsma and I started a Yi podcast: Casting Changes: Podcasts about the YI in Times of Movement. The first podcast is available now - an introduction about who we are, what we do and what we are going to do with the podcast. Including the examination of a hexagram that is representative for our new endeavour! If you want to watch the podcast and be informed of new episodes you can sign up here: https://castingchanges.projects.webpages.one/ This is going to be fun!

There are not really 'correct' colours - it depends on the source and era what colours are assigned to each trigram. The Shuogua chapter of the Ten Wings will give you some colour associations, but often the colours are also derived from the Wuxing connection with the trigrams.

See for a study and translation of the Mawangdui Yijing and its commentaries I Ching (Classics of Ancient China): Shaughnessy, Edward: 9780345421128: Amazon.com: Books.