Yes, a natural disaster is a disaster made by natural that we generally cannot control, however a terrorist attack is all done under the power of a human being. If all human beings had morals and respect that wouldn't happen. So yes it is a man made disaster.

Yes, terrorism happens when two political ideologies clash and the less powerful one is forced to resort to alternative tactics because of a lack of resources, I look at it as David v's Goliath.

One mans terrorist is another mans freedom fighter

Yes. Even if some claim it's an "act of God" (speaking of their own deity), it's still people and not weather or plate techtonics.