It would be lovely to see how the game plays and all, but unfortunately, this baby crashes the first moment you run it -- whether it be within the Editor or not.
Fortunately, I saw to it why that was the case. Since you're using some translation version of RMXP (or the Japanese version what-have-you), the game needs RGSS100J.dll. Got that downloaded, started the game up, and whoop-de-doodle.
...And the first thing I noticed. Why is Up configured to Up arrow while ASD are configured to their respective directions? It's inconsistent, personally.
You'll probably want to study up a bit on some eventing. We can easily pass through that Prologue Event if we don't press S, haha. This is where you use Autostart, which makes the event run automatically without fail...Then we can just Erase the event once we're done.
There's a lot of...hm...Newbie stuff here indeed. For instance, on your maps, there's a lot of negative space, especially outdoors. The real world isn't full of emptiness (Unless you're in like, what, purgatory? :v) now is it? It gets really dull and boring to travel throughout places in these empty environments. If you want to learn some awesome ways of mapping, look at other RPG Maker games!

There's also the Mapping Improvement Thread in General RPG Maker Discussion.

Story-wise, not bad. I'm sure you can tell a great story...However, with just some more execution skills it'll get even better...Though personally, those Harry Potter spells really drew me away from the whole atmosphere.
Just learn a bit more around this editor and you'll do fine...I can't think of anything else to say...so...yeah. Good luck.