Currently the Game Design Support category serves as “Anything that doesn’t fit elsewhere” category. I find this rather uncomfortable as I enjoy talking about game design but the category title is misleading and the actual game design-related topics are only around 50% of the topics there. To make the Help and Feedback category more clear, I suggest adding one of the following solutions:
Add a new sub-category, called “Miscellaneous” or just “Misc Support” for topics that don’t fit into any other sub-categories in there, leaving Game Design Support for what its name suggests
Alternatively, if the amount of game design-related topics turns out to be too small (though I doubt that would be the case), simply rename Game Design Support to Misc support so that its name matches its current purpose
Then “Misc Support” would become the topic that people not only put things that belong elsewhere, but people are also going to ask questions that are not related to development.
Most of the questions in Game Design Support that are slightly off-topic such as TOS (can I put _ in my game without it getting banned?) questions or Studio related questions (how do you do _ in studio).
I disagree with making a “Misc” section, but a Studio Support section is much-needed right now.
Maybe it would be better if instead of subcategories, help & support more heavily relied on tags and have better moderation on those so that you can use tags to dynamically filter content you want to see.
Misc content would just be content without tags, and maybe certain highly-active users/moderators would be able to add or amend tags on the topics there.
Apart from the problems you already mentioned, the current category division is also bad because some questions simply have no place that should be askable (like studio questions, “where do I do X in Studio”) and the categories are heavily unbalanced (Scripting Support gets way more traffic than Building/Design support).