Pruning lower branches is not a bad idea at all BUT you should do it before you get buds on them... ideally about a week or more before initiating 12/12. this will give the plant time to repair/recover. And you can use the pruned bits for clones.

As for fan leaves... leave them. Even though they might not be getting a ton of light, they serve as repositories for mobile nutrients such as Nitrogen, which the plant will tap into as it nears the end of its life cycle.