Then there's your answer for most projectiles that even have a chance of hitting. TJolt's unique properties are what it amazing for counter Planking.
Right, I forgot to mention: attacks with transcended priority don't clash AT ALL, which means any projectile will go right through them. (Think Falco's laser)
Alright, you want an in-depth list? Keep in mind that you can spam all of these until the timer runs out, and all you need is enough hits to gain the percent lead back.
Flame breath (Charizard/Bowser): Shorthop into flame breath over the edge and there's little MK can do besides dropping down beneath it and flying around it, at which point you've stopped him from planking.
Bananas/Peanuts (Diddy Kong): Peanuts can be arced fairly close to the ledge and bananas can either be spawned or thrown toward him. Both can be caught, but you can mix it up.
Iceblocks (Ice Climbers): Fall right off the edge. Self-explanatory. They can be hit back, but desyncing cleverly or punishing MK if he uses fair should get at least a few hits in.
Razor Leaf (Ivysaur): I dunno about this one; no one cares about Ivysaur.
Bombs/Boomerangs/Arrows (Link/Toon Link): Bombs have a lot of freedom in their use; mix it up and you'll land one. Boomerangs are easily predicted, though, and probably won't hit. I'm not sure if arrows arc far enough to even hit someone planking.
PK Thunder (Ness/Lucas): They both work essentially the same as far as stopping a planker goes. You can mindgame with these. Start them from a safe distance, and you can run them into the floor and be out of the lag before MK can punish you.
PK Fire (Ness): Use it in the air and it'll shoot diagonally. Punishable.
PK Freeze (Lucas): Start it from a safe distance in the middle of the stage and MK won't be able to punish you. You can still see it coming a decade away, though, so it probably won't hit.
Fireballs (Mario): Fireballs > planking, simply. Just throw them at the edge all day. Luigi's screwed.
Thunderjolt (Pikachu): Yeah.
Arrows (Pit): Fire 'em up and loop 'em down on him. Plenty of opportunity for mindgames here.
Gyro (ROB): See the Links' bombs, although it takes longer to get out.
Bombs (Samus): Just jump above him and drop them on him.
Grenades (Snake): Toss them from the other side of the stage and use Snake's magic control of grenades to make them fall right over the edge.
Din's Fire (Zelda): MK's only answer to this is airdodging or ledge invincibility. You'll get one in eventually.
And Donkey Kong in no way has good options to deal with planking. The options you have listed there will work if the planker is blind and/or sleeping.