Yeah... I took off fan leaves on my first plants. I'll never do that again. Think about it, what absorbs most of the light... The large fan leaves, thats what their for. IMHO its not a good idea to take off healthy leave above the top half of the plant. However completely cutting of the bottom 1/3 of a plant will help allot. That is called lolipopping. Just take off lower leaves and ones that start to turn yellow espesially near end of flowering.
This is just what I think though , as well as everyone I know that grows.
If your gonna take leaves off use moderation.
Again just my opinion, everyone has their own methods and you gotta find yours.
btw you start lolipopping once when they are young in veg, then trim out more if needed a week before flowing.