Q32. Do you use tags? If so, what do you tag? If not, why not?
I do use tags! I use my folders for basically which fandom or story-verse each character belongs to, so the tags usually are for more general things. Gender, type (humanoid/anthro/feral, for instance), RP (those that have the RP tag are open for it), and original species are some of the most common tags I use. If the characters are part of a fandom, I will also list that fandom as a tag, as well as their specific race/species if applicable, so that interested people searching for those tags might come across my characters. :)
I find them most useful for grouping up characters in ways outside of the folders I've put them in. For instance, if I want to show someone all my anthro characters, or all my female characters, I can do that easily.
Q33. Which of your OCs like to cause trouble the most?
As far as deliberately causing mischief and mayhem, Rich is the one who enjoys that most. He is amoral and really doesn't care how he affects other people for the most part, so he finds it amusing to unleash his latest projects on the world and watch authorities scramble to clean up the mess. Making chaos and watching others' reactions is incredibly entertaining to him. He doesn't deliberately try to hurt other people unless they are an imminent threat to him, but he wouldn't feel bad if someone did get hurt.
I'd have to say that Koyasha is the one who likes deliberately causing pain and torment for others. She is very sadistic and has no qualms about killing others, but if she can torture them (either mentally or physically--or both), that is even more amusing. She will go out of her way to target specific people she holds a grudge against, and then will use and harm everyone close to them to torment her target all the more. Anyone and everyone she takes notice of will probably be affected by her cruelty eventually.