Here are the character to character chain grabs: (most characters basically mean fast fallers and heavy weights.)
Bowser- all characters, Wario I don't know why you mentioned all characters AND Wario...but yeah I'm pretty sure Bowser can't CG DK
CF- Wario Also MK
Charizard- Ness & Lucas
DK- all characters, mostly Ness & Lucas He can't CG all chars, wtf. Only with a wall
Falco- all characters
Fox- buffer on most characters Nope
ICs- need I say more?
Ike- Wario
King D3- all characters Nope. He can't CG anyone lighter than Marth
Kirby- most characters Pretty sure this isn't true. Maybe like 1 or 2 regrabs on a few chars? Definitely not 'most'
Link- most characters LOLWAT
Lucario- most characters SideB chaingrab isn't true cause you can mash out very easily, uthrow only on some fastfallers
Ganon- all characters Oh god no
Mario/luigi- all characters Nope
Peach- all characters I know it's on quite a lot of chars, but I don't think it's all.
Pikachu- all characters Same as Peach
Pit- most characters At most, same as Peach. At least, only a few. So this one might be right.
Olimar- all characters Nope.
Samus- Wario
Sheik- most characters Nope
Snake- all characters Nope
Sonic- all characters Nope
Squrtile- Ness
TL- Link, most characters Nope
Wario- most characters Only a few
Wolf- all characters, Falco, Wario Nope
Yoshi- all characters A lot, but not all
ZZS- most characters, Wario, Squritle Nope. Heavies with fthrow, Pikachu MK Lucas Squirtle Wario with air release
The following information above might not be accurate, leave your suggestions to tell me about any mistakes, I'm a new player.