Funny you mention this, because I was playing vs. my friends Zelda on FD, and I was on my last stock at like 150%, hanging off the edge. So I decided to try to make it to the other side, and I was close. After that match we decided to see how many stages ICs can get around.
We were going to make a video montage, and we had the replays of ICs making it under just about all the stages you listed, but then I realized that my cell phone can't send videos that are over like... 18 seconds, so I had no way of getting any of them to my computer. I just ended up deleting all the replays.
But I had a harder time getting under FD with D3 than ICs (wow that's a lot of abbreviations). I found it to be easier if you hang off the edge, tap backwards, then quickly tap forward. After a few tries it became pretty easy. D3 took me like 50 tries to get around. You have to time/space his jumps perfectly.
For some reason, I'll hit it to shoot up a HUGE distance, and then try it again but faster, and I wouldn't go half the height.
I'm convinced there's a certain method to do it.
Either that or I'm an idiot.
Yeah, I think if you go too fast... it's almost like some of the button inputs wont register. Without going as fast as I can, I usually end up going just as high, if not higher, then Popo gets launched with up-b. Then I'll try ramming it as fast as I can, and I won't get as much distance.
o_O I'd also like to see a vid of (both) IC's going under and making it back.
I mean, it's pretty easy to imagine IC's going under FD
...and SD'ing.
Sonic can go under FD with some aid of Homing Stall, spring>walljump under the edge.
However, I'm cool enough to be able to use Sonic and go under and around FD without having to resort to that.
MK can also glide under FD, rise up a bit, and use up-B to get onto the stage.
I'm kinda surprised at the Wario and Luigi ones. I've never tried ;O
Luigi isn't actually that hard, especially if you get an overcharged torpedo. Just full jump and start charging the side b, get to the other side, use the second jump and tornado up.