Hey hey, always love to hear ideas :D I think that this right here may be the best place to send ideas so anyone else can see them too. But if you prefer to send a private idea you can send it to this mail n2mainemailcontact@gmail.com
As for adding new characters i currently have 2 that i am working on, 1 is coming in the next update.
The good thing is as i build the game making new characters becomes easier since we can reuse and remix mechanics. Keep an eye out on the patch notes, in an update or two, you may just see your character appear :D