Normal mode is for just a regular game. If you want to play lee or morg or whatever, sure, do it. If you want to try out a new build, also fine, go for it. First time with a champ? Sure play normals.
Normals is *not* the place to solo queue and do things like, attack speed soraka. That would be trolling. Trolling doesn't have a place. There is no "it is only normals" if it is going to get you busted in ranked, it should also get you busted in normals. Now some of this is because people not only take normals too lightly, but people also honestly take ranked too seriously.