First off, welcome to the forums. Now to answer your questions.
1. You can manipulate pretty much all behavior parameters at runtime, and that includes the two you mentioned.
2. There's no condition like that, but here's how you could do it: every enemy has a value called "spawned". For the sake of the example, this should have a default value of 1 so it's that value when the object is created. Now check if a ghost has a "spawn" value of 1. If it does, then you can set the angle, position, whatever. Then simply set the spawn value to 0 so the event won't trigger for that enemy anymore.
3. It is rather simple to do with events. At the start of the layout, have the width of the background set to LayoutWidth and the height set to LayoutHeight. For this to fill the whole area the background needs to be flush with the top left corner of the layout.
4. Do you just mean zooming in? Or where the layout is seen but with borders around it? If you're just talking about zoom, it's a simple as going to the event editor and setting the zoom through the System/Set Zoom action. Or you have it zoomed in out on startup using the layer properties.
5. Split screen games aren't currently supported, unfortunately, and as far as I know there's no way to do what you want with multiple views. I think the devs have plans to implement them at some point, although it might not be until after 1.0.
6. I think that's the way it's intended, actually. I don't really know if there's a way around that.
Anyways, I hope that answers all of your questions well enough, and I hope it helps