I'm not sure if I'm the only one have problems with this. But it seems to me like for a lot of match ups, once you're off-stage, you're basically done for becuase of how ledge grabbing in the game works. For example Ichigo V Megaman. Once you're off stage, you better hope that you're above stage, because MM can use N-Special once you get back and there's nothing you can do about it.

Do you have to fall onto the ledge to grab it, or is there snapping to ledge that I don't know about?

You have to be very close to the ledge to grab it (or just use DK and Up B right into it). Smashville has some stupid extra that you sometimes just cant grab ledge if you hold towards stage (simple solution: dont), but thats about it. This isnt Smash 4 with its stupid magnetic ledges, recovery is supposed to take some sort of effort Of course everyone in this game has a great recovery anyways, but I digress.

Ichigo in particular can just dip low, use Up B and pretty much grab the ledge for free if your spacing is on point because the hitbox is so ridiculously huge its not even funny.

I know it's supposed to be difficult. But I've run into situations where I literally just can not get back on stage because of the match up. Take the example I gave.
's fully charged neutral-special is probably one of the best ways to cover the ledge because if you time it right everytime, it'll hit the character just before they get onto ledge.