Hi Thorsten, generally Toolset Support does not make Custom Code (https://toolset.com/toolset-support-policy/).
Usually, for Custom Code, we'd recommend you reaching out to https://toolset.com/contractors/.
Both Custom Codes provided (https://toolset.com/forums/topic/alphabetical-view/page/2/#post-1241580, https://toolset.com/forums/topic/split-alphabetical-view-conditional-check-of-tags/#post-1241642) are at the limit of what's supported, given it uses the Toolset API it's something we can help with and review code, give ideas and information or explanation and examples of the API.
But we cannot assist development and in-depth assistance of such code, since theoretically, everything done within the API calls is Custom Code - this is similar when you use other's API such as Bootstrap or any other.
To work with the API and WordPress API + PHP, usually, long term coding knowledge is required, this is why we cannot assist with the entire programming and deliver ready to go code.
I personally don't think I can help further on those codes, as they are already quite elaborated, with lots of custom lines of code written which should be explanatory for the Toolset and WP API.
We can as said not produce custom code that is ready to go or elaborate on details where Toolset API is not anymore the central doubt.
What I can surely help with is the setup of the View you mention.
"shows a list of all related articles and than you should click on one of the articles to get to the article."
Do you mean, that you want a list of posts that are related (in a post-relationship) to a post you choose, and with a link that leads to those single posts?
To help you with this I'd need details such as what Relationship this is. You will, in any case, create a View and Query the Post Type you want ultimately do display its related data.
Then you'd add a Query Filter to that View, stating that you want to filter posts in the XY relationship you chose.
In the Loop, you can then display data of the post queried or data of the related posts by using the Item ShortCode attribute (when you insert ShortCodes you'll see an option to choose from what post to display data).
For now, I can pass this documentation where you can find more information about how to display related data:
General: https://toolset.com/documentation/post-relationships/
Display: https://toolset.com/documentation/post-relationships/how-to-display-related-posts-with-toolset/
Display related data: https://toolset.com/documentation/post-relationships/how-to-display-related-posts-with-toolset/displaying-related-child-posts/, https://toolset.com/documentation/post-relationships/how-to-display-related-posts-with-toolset/displaying-fields-of-grandparents/
Please let me know if you need an example view on the site, I activated a private reply in case you need to share access to the system.
