to answer your z-lightshield / shield-drop question:
I don't think it's anything specific to Ganondorf. In fact I don't think it's specific to lightshield or the z-button
The way I understand shield dropping is this: there's a certain distance that you have to move your control stick down in 1 frame in order to drop through a platform. There's also a certain, larger distance that you have to move your control stick in 1 frame in order to spot dodge from shield. So basically if you move the stick too far/ too fast, you'll spot dodge, and if you move it too slow/ not far enough, you'll just angle your shield downwards without dropping through the platform.
It just so happens that the vertical / y-axis distance between putting the stick fully 90° left or right, and putting the stick at a 45° angle, is just right - not too far, so it doesn't spot dodge. So basically all we're looking at here is an easy setup for satisfying a few conditions to make shield drop easier:
- in shield
- on a platform
- stick fully 90° left or right (not rolling)
the "not rolling part" is tricky. basically, you need to already be holding left or right on the stick when the shield comes up. otherwise, you're going to have to slooooowly move your stick over to the left or right to avoid rolling, and that's not easier than just shield dropping normally.
as for it's usefulness... shield dropping is godlike, you get to skip Ganon's 6-frame jumpsquat and basically perform any aerial oos, five frames faster. you also end up below your opponent while they're stuck on a platform, which is another bonus. so any setup that makes it easier to do is definitely beneficial.
Well I already do that except I use Z instead of L or R for the lag cancel, I just do the aerial, while holding the directions and without worrying about an accidental grab coming out, and since I'm already holding the light shield just comes up which covers Ganon's entire body, so he's no longer susceptible to shield pokes. Maybe I'm explaining it wrong, but I'm sure it has uses for it. Lab harder bro. lol
however, if you're using cstick to aerial, I guess you can just do this:
1) use cstick to aerial
2) when you l-cancel, keep holding your l-cancel button down
3) hold control stick left or right while landing
that way, once your landing lag is over, you'll be shielding and angling your shield 90° to the side. then you can just slam the stick to the 45° once you want to shield drop. shouldn't be too tough to get consistent with this setup if you practice it a bit... but the feeling of holding down the l-cancel input is really weird.