such an idea has already been suggested : https://feedback.worldofpotter.eu/communities/1/topics/1277-nonbinary-gender-option

This is not realistic at all as there's no spell of this kind mentioned in the HP series. Moreover it'd have to be an extremely difficult spell for NEWTs-level at least. 

It is your Plot Team's job to build up such plots and activities for the whole site, so I suggest you to talk to one of its members ;)

it has already been suggested here : https://feedback.worldofpotter.eu/communities/1/topics/1110-sell-your-stuff-vs-gallions

it is already possible by typing several names in the receiver box.

https://feedback.worldofpotter.eu/communities/1/topics/554-trade-chocolate-frogs-cards it's planned ;)

if you deposit your money at gringotts you can't lose it, and you get 1% interest everyday ;)

Oooh saw it ! Well, I like this idea, but not much is known about magical art, and this theme is already taught in most Muggle studies curriculum. Also, only VIPs can upload pictures for their homework ;)

What would young witches and wizards learn in an Art class ? Do you have an idea for classes ?

it is normal, it is a VIP privilege to access the mobile chat ;)