dang I miss Melee. Melee felt like you were in a tournament Single and Multiplayer.

I'd like some new characters. Take away Wolf, R.O.B. and Lucario - replace them with new characters such as Isaac and maybe an Animal Crossing character (millions of copies sold confirmed in Japan) and would love some third party characters via DLC

Let's just say that they were all removed for a reason.

Dr. Mario or Young Link the other are all the same clones and would add nothing to the game.

Roy and Mewtwo actually have some files in Brawl, and Mewtwo has more data then any other partial character. They are also fairly requested characters by the Japanese Smash fans, so it would have to be one of the two of them. I definitely could see Dr. Mario coming back as a costume though,

All of them, plus all new characters from Nintendo and even more from third party developers, I would hope so.

Young Link and Dr. Mario (and Pichu, to a degree) are the most similiar clones to the originals, so I don't see them coming back.  Especially Young Link, since Toon Link basically IS Young Link.

For those that don't know, Brawl contains place holders and some data for 7 characters that did not make it into the game (the reasons they were cut is not known).  Theses characters were Roy, Mewtwo, Dr. Mario (which could be a reason Dr. Mario is not a costume for Mario), Dixie Kong, Toon Zelda, Toon Shiek (could be Tetra), and Plusle and Minun (likely Pichu replacements, maybe Iceclimbers style.)  Out of all of these, Roy and Mewtwo had the most data, so I would start with them.

I want Mewtwo to make a return if they can improve his moveset (his down and side b moves just always seemed useless to me) and Young Link if they make a moveset for inspired by MM with transformations and such (preferable a Fierce Deity transformation) and not just a copy of Link but faster.

Mewtwo with a different moveset

Mew Number TWO.