Infinite categories sound great, though some bozo might end up crashing the fucking site doing so.
Is this low level trolling? Can't tell.
Everytime someone suggests a feature without saying explicit limitations, someone just has to go "oh so it's no limits? how's that gonna work?".
Categories for the glossary? Honestly you could just put everything in a single glossary post and update/edit it. Have a "Contents" section, for each entry in there, also write a 'password' so that people can ctrl+f their way to the right place. It might sound bad, but I hate having to open 3 thousand tabs.
"Too many tabs" is the reason why qidian is doing well, you can have 1 tab per story there, and preload 1000 chapters if you want (although it's a pain to do so). Contributing to the "too many tabs" issue isn't great.