Some suggestion that came to my mind: (I know its long but don't skip it QAQ).
#1 : Since you do have a virtual money system, you should add something that allows people to spend the Weebs. Of course I support the idea of awards, but I don't think you should set up a system where one can buy awards. They should be earned, not bought. You guys could make it so that the custom usergroup can be bought using Weebs since you're only giving one of those. Or maybe VIP membership...well there are many possibilities.
#2 : If you do have a buyers marketplace, why not a sellers/traders marketplace? There could be people wanting to sell their services. You could just integrate all three (buy, sell and trade) into a single forum and make thread tags.
#3 : As far as I know, MyBB doesn't come with the spoiler tags, so the [spoiler] Its a spoiler! [/spoiler] doesn't work as you can see. There's a way to use it with HTML but that's just too time-consuming and inconvenient. I would hate to give or see spoilers in the Anime Talk and Manga Talk sections. You could set up the custom MyCode. Its pretty easy and I think that spoilers tags are desperately needed.
#4 : You have technology, gaming and graphics forums, so what's stopping you from having a music section as well? WITH A VOCALOID SUB-FORUM IN IT, OF COURSE (^).
#5 : This one isn't really needed, but you could have a thank you/like system. There's plenty of those mods which are compatibly with MyAlerts too.