Gonna voice opinions on the cast as it is now:

Revamp slightly. Make him more like his Melee self, with improved F Air and a stronger Fire Ball.

Down B is now Poltergeist. Make it similar to Fludd, but able to charge while walking

Keep the same more or less like her Brawl self

Boost stats all around. More power, more weight, and make him bigger. Fire Ball option instead of Fire Breath would also be nice. And Melee Up B needs it's return. Badly.

Keep his Brawl self, but with an improved Neutral Air, the roll as a dash attack for rush down options and a bit more power on some moves as F Air, F Tilt, N Air and maybe a stronger jab. Love playing as him in Brawl the most still though!

Different Down B. Possibly the duo Peanut Pop Gun ground pounding move, with a tripping or stunning effect on impact. A little more power on F Air, and perhaps a different Neutral Air (tail spinning attack). A little more range on U Air to. Otherwise: keep him the same. Please.

3rd jump option by holding the jump button. Longer range on tongue attacks as well (like grabs and stuff).

Less aerial mobility, make him more of a power character. Maybe remove the bike as well for the shoulder charge (and give the bike to say, Mach Rider).

No more bombs and boomerangs. Say hi to the Shield Bash and Skyward Strike. Better AAA attacks, more speed and definitely bring back (PAL) Melee's Up B. Maybe fuse with Toon Link if he's gone.

Down B with a duo tag team attack switching into Impa

. More balanced stats all around. Change B Air into something else than a F Air carbon copy. Make D Air and D Smash different, and improve her zoning game even more.

Remove as a character. Spiritual succesor: Impa.

Ocarina of Time inspired moveset, further Luigification from C.Falcon. This is a must.

Either remove and replace with the likes of Ghirahim (ugh) or Tingle (double ugh) or chance into something less cloney than Link. Keep the bombs and boomerang for a "Classic Link" playstyle.

Less weight, slightly speedier attacks, faster shooting. Chargeable missiles, Morph Ball mode for Down B, uber combo Screw Attack (with double jumping a la Pikachu's Up B)

Keep her in, and don't change her too much.

New Side B inspired on Uprising.

Keep them in, remove wobbling if they can. :/

Keep him, got an unique moveset and stuffz.

Keep him as his Brawl self basically.

Nerf.

No more chain grabs. Distribute his power attacks better to...

Less weight maybe.

Could stay more or less like his Brawl self imo

Same, just remove stupid stuff like chain grabs and laser locking.

Keep him, and let him stay just about the same

Make him his Melee self again. Better hitbox on the knee, but not as great as it was in Melee

Lighter weight, smaller frame, less power, more combos. Static ability: paralyse effect on some attacks which make direct contact with Pika. And, Quick Attack is now 3 jumps, Skull Bash is now... another attack. Iron Tail maybe? Thunder Jolt is more powerful and can stun at higher %.

B is now Bubblebeam and does damage. Side B increases Squirtle's weight, and can be held down to "counter" or block attacks. Can create an oppening. Running side B is still the same attack. Up B is a stronger attack for offensive purpose, and travels a little more distance.

Side B is faster and stronger. Up B is stronger. If Down B is free: it'll be Poision Powder, Sleep Powder and Stun Powder. Each time a random effect.

More speed on his move, far better flying and gliding (think Pit). Flamethrower can be used in the air and lasts longer. Rock Smash is gone for Wing Attack (double tornado version from 3rd gen). Fly goes much higher and automatically goes into gliding mode. If Down B is free: Overheat. Less weight to.

Remove the increasing power with higher damage %. Make him play like as if he has around 60~85% damage.

Make Sing useful, and Meleeify her a bit like C.Falcon.

Keep him more or less like his Brawl self, but a little more weight, and a little little slower.

Up B is now a realistic Aether that can heal damage when all hits connect. B is now a ranged attack. A little less knockback on his moves, but a little faster also.

Mortal Damage. Explained this before. Remove PK Fire and PK Thunder for PK Rockin' and PK Teleport. A few more moves need to make use of the bat (think F Tilt).

More or less the same as Ness. Except PK Rockin' is PK Love.

More or less can stay like his Brawl self, but less predictable. Remove some knockback on his Up Smash and F Smash. Make him more annoying and less powerful.

Less weight... my God. Link / C.Falcon weight at best. Less overpowered hitboxes, less power and more other stuff. Keep his defensive game.

I really don't know / care
:mewtwo: Everything I once explained. Basically buff him up, especially in regards of power, priority, range and weight. New B moves for Confusion and Disable.

Don't want him back. A possible 6th Mario rep but mehh... :/ Why would they? Make him like his Melee self if he returns. As in: a full clone. Anything else doesn't make sence.

ichu: Discharge effect on his moves, attacks don't realyl hurt himself unless discharge comes into effect, or Thunder hits himself. Don't really want him to return though... But Pichu at least is cute. And stuff.

Ranged B instead of melee ranged. A few heavy sword swings a la Ike here and there, but more or less would still be a Marth semi clone really. Don't really expect him to return, but maybe as a 4th rep.

No.