any thoughts on subcategories vs categories? Not sure what makes-a the sense …
Yes: the less the better 
. No one tend to stick to them ver much (at least not in actualism where, as @Alanji has said, we are not very thread disciplined either)
It’s better to create them as needed BUT then the moderators/administrator have to enforce users to used them, move messages around, etc. It’s more work if one really wants to make the categories work.
So, is good to have music or random so that stuff is not going to general, but I don’t know if, for example, “method” vs “experiences” would be categories respected/appropriately used…