Hey Sam! :) I think tags are a great solution when you need to use a has_any_belongs_to_many relationship to a ‘category’ but want to avoid writing join tables, however, if your Categories need more complexity, you may be better off writing the table manually. Let me know if you need help with that!
For following, I recommend just plugging in a link to a font-awesome icon. Their icon set is very versatile and includes more Chinese social media (for WeChat, an image of the QR code is always best). For sharing, iirc the UltimatelySocial WordPress plugin has lots of options for Chinese social media :)
Great article! You cover the basics well, but there are a few typos with active record(i.e. using User.all, not Users.all). It would be awesome to see a more in depth article explaining the ins and outs of CRUD.