Okay, Nightmare Soldier- fine. Impmon, Possible. Kuramon gets tricky in that mostly, it's Unknown, which is hard to deal with- more of a Non-Family, if you will. Plus it's a bit too much potential to start with, due to its origin. I do apologize, but you understand, don't you? It feels like something that'd need an expansion module/extra setting to deal with.
 Now, Dracmon brings a whole other set of issues in and of itself... mainly that I planned a certain NPC to appear early on, and having a player Dracmon might cause... static, if you will. That said, Dracmon would be difficult to earn, and after you see the way the corebook works, you might even find you'd rather another Nightmare Soldier.