I have had this happen to me as well. One thing I noticed is it always happens on quests I don't currently have unlocked for offline play. You can still join levels you don't have, because someone else made it. But you cant create an online parallel if you dont have access to it offline. However. Even still. I've found quests I do have, even i ngames i've created myself, still end up not getting cleared officially.
I have no definitive answer. If you find one, that would be great to know but so far I think a) it's a RNG problem. or B) someone else on your team didnt have the quest, thus, they didnt get a clear either, and so by default you are denied the clear.
It has been awhile since I played, but the way I remember this working is that the Ultimate Finish, IE, the extra step to occur, is completely random in most cases.
So, for this stage, activating the final objective, simply has a CHANCE to occur when you Defeat broly and turn in the first 3 dragonballs.
So, you need to defeat broly, then turn in the 3 dragonablls. If Broly doesnt revive, you didnt get lucky. Keep doing it until it happens.
At that point, Broly is stronger and you can let him beat videl and the kids, or, If you just defeat Broly in this revived form BEFORE Gohan dies(Which includes him never showing up), I THINK, you get credit for number 2. To be safe, you can let Broly beat everybody up while you gather 3 of the remaning 4 dragonballs. Then, wait until broly beats up the two kids, and when Gohan appears, finish him off.
Best Answer
No, every character has his unique grab. So do all the different races and sexes. If you made a saiyan male he will have a different grab than a namekian.
Shame that you can't learn new throws because some characters have seriously overpowered throws and the created character not that much.