1. Normally when you ask for a sprite on the forums you specify what dimensions you want it to be, what it will look like, and what style you want it in. Without that people can't really help you. You may not be picky about what the character looks like but it makes things easier for others who want to help.
2. If you want ideas for enemies it would help to know what type of game. Without knowing how the game is supposed to go, it is hard to come up with relevant enemies.
3/4. There are plenty of tutorials on scripting, again you need to be more specific. If you look at the tutorials general scripting is pretty self explanatory, but again it depends on what you are trying to do and how much you know. Look here for some basic tutorials.
http://game-editor.com/Tutorials5. If you save your image, you can load the image into gameEditor by clicking [Add Animation] on the actor control panel.