Banners are a work in progress - they actually have that asset in the game's files. The devs will get around to it eventually. And if not? Modders have already worked on it.
As for your second request... basic Mount and Blade has always been a low fantasy setting and so dragons aren't on the table. However, there are already animals in the game besides horses( wander around a Vlandian town and see a goose). In the mod Brytenwalda and (I think) the Viking Conquest DLC they did have animals like deer you could hunt. However, I'm not sure what is going to be implemented into native.
Frankly, this isn't the best place to post suggestions.