Tripping-
Doesn't really need to go. Remember, this is basically Melee 2.0, not Melee itself. Forced tripping was not in Melee, but new ideas are welcome. Random tripping is obviously a no.
Chaingrabbing-
CGs are often looked down upon because players don't like to watch as their character is juggled by the same grab over and over again. Chaingrabs were also a major problem in Brawl, especially considering how they were one of the only few forms of real combos, and were easy to start since shieldstun is next to nothing in vBrawl. However, in Melee, CGs were one of the only things keeping space animals in line. I'm going to restate the example of Marth vs Falco in Melee. Marth pretty much had no chance against Falco in Melee. He got pretty much wrecked UNLESS he could land a grab. While of course, some unnecessary CGs should not be included (such as Ganon's/Sheik's), CGs actually helped to balance out the space animals a lot, who I'm sure will once again be deadly forces with some of their old tactics back in play. And keep in mind that landing grabs is much more difficult in Melee than in any other smash game. Put simply, some CGs are obviously a no-go, such as ICs infinites, but some CGs actually help the game balance a bit, and in my opinion should be included.