I use the analysis board for the very same thing! I usually find a move I'm not too sure about, then try and find alternate moves, looking ahead about 6-7 moves for each. I've found its a very useful tool for learning to look ahead.
I don't see it so much as a crutch. It allows you to look further ahead then you'd usually be able to. I suppose it's possible that some players could develop a dependency to it, but most people will still play as well, if not better, without it. For my part, it hasn't helped my online games when I don't use it, but I feel that my physical games have improved somewhat.