yeah i removed fan leaves once in mid veg, and it turned out to be a pretty decent idea! but i would never do it again [it was my buddies idea]
thing is, the light might not penetrate as well, but the fan leaves are what COLLECTS that light and turns it into energy and sends it down the branches.. so in direct light or not, it is still getting the energy needed to grow the way it grows in nature!! if its really really bushy, trim some lower branches, and maybe tie some branches down to get some air flowing through her... peace!