Some good ideas!

In fact, some of these are really popular ideas: Your second idea is basically a map builder, which they already said they are working on, we just need a little more patience. A following camera is also something that has been suggested a couple times, many people seem to like the idea. And modding support is something many people would like to see as well, you might want to take a look at the "Unoffical Modding" forum section, some people are already doing it without official support!
In general, take a look at the list of all suggestions, maybe you can show your support in some of the existing threads, it helps show the developers a feature is really wanted

Archers with fire arrows is also a cool idea, add some more challenge to the game