I've never thought of strategy guides as cheating. Heck, I don't even think cheats in games like GTA are a form of cheating. In this case though, I think using strategy guides for FF2 is indeed cheating. FF2 is quite easy to complete and it would be better to handle the challenges as they come. I am not a person who likes to get stuck on a certain level for almost a day so I would probably study the strategy guide. I didn't though. By the time I was playing FF2, I was already done with FF6-FF9.
I think game guides are used to have a complete way of experiencing a game. They are detailed and will guide you to enter secret areas, fight optional bosses, see easter eggs, etc. that could only be done if you have the guide.
You could get spoiled in the story if you're playing the game using a guide. For me, I would play using a guide if it is my 2nd time playing it to experience things that I might have missed in my first playthrough.
I think people are confused with what qualifies for cheating. And what qualifies for the strategy. For example telling the users to follow certain direction is strategy. Where as use "XYZ GHS" in the console and enable the cheat to play in god mode. That qualifies for making use of the cheat. So strategy guides are helpful but here you don't cheat.
Looking at strategy guides is not cheating. On the other hand, using 'cheat codes' now that is what we call cheating. But then again why would you want to use strategy guides, unless you think you are weak and you can't beat the game using your own brain.