SEO problems after installation

Hello

After some study, I finally install discourse and start to operate a forum site in Korean language. Congratulation!

However, after I operate the forum website I have some SEO problems so I need your help.

I read all of articles in the meta.discourse.org, but I couldn’t my solutions yet, so If you know some solution using Discourse, please let me know.

Category Index remove

I believe that category is not effective for SEO purpose, so I would like to delete all the results from Google, why don’t you give an option which is not opened to the public of category created link like
https://meta.discourse.org/c/createdcategoryname ?

Category description remove

like Categy Index remove, I don’t want to open the Category description to the public,
https://meta.discourse.org/t/createdcategoryreason

robots.txt

Google announce me robots.txt have some problems, Isn’t there any option for change robots.txt by my own?

Structure data

I couldn’t pass for the google Structure data test, is there anyone who can pass the google structure data test?

Canonical URL

Some search engine like Never(Dominant search engine in Korea) recommend to change the link for the canonical URL, do you have any recommendation for that?