How else would someone do some mouse / keyboard automation for cheats for games, like say some flash game, would SCAR be the best way to do it or would a specific language also suit this quite well?
For simplicity I'd actually say the newer .Net languages are better. There are classes which will cater for EVERYTHING he wants to do, whereas with VB6 you need to make WinAPI function calls which can be a pain.
You could always use Java with very little hastle with some pre-built open source methods for finding color and images. Check the Java section, rather search the Java section, because over a year or two ago I posted some open source code for image and color finding methods. Note, very remedial ones, but for your use they're simple to learn with. Then you can move up to bigger, better, faster and more accurate pattern recognition methods based on these fundamentals .