This is a debate that is always up in the air, if you want to play items good for you but playing with all of them adds a random factor that can hinder you more than helping, say you air dodge grab a capsule and go to throw it at an enemy, suddenly an explosive box drops from a spawn point close enough for it to explode and kill you. How is that a strategic ko for the opponent?
There was an official item legality thread somewhere on SWF. It eliminated all the dangerous items.