Object and vouch if youve done so previously.
Hats - Can be bought in shop, are buttons with specific model data. Requires texture pack which if done /resourcepack will make a resource pack popup
/pc - Pay coins to an other player, will be logged in a other command.
/auc - Auction some items for coins. (Before objecting saying they can be copied, it's just for new items or people who want it, you arent forced to bid on things, it could also be for early distribution of a kit or other.)
I forgot most of my other suggestions, so if anyone remembers some, tell me!