You can say whatever you want. Toriyama colaborated with Daizenshuu, but who tells you he participated in movies apart from designs? I still maintain my position. But there is no problem, you like some chars I dislike, but that is no problem.
I think Broly is powerful, but not as powerful as a SSJ2, he is very far from that power, as far as Cell.
I failed about Toriyama, sorry. I meant TOEI. Anyway Gohan was SSJ2 and you can't deny it since it's confirmed by the creators. Plus there would be no reason for Gohan not to transform into SSJ2 since he has mastered it long ago. Note that this movie most likely taken part after Gohan trained with Goten.
Broly was less powerful in "Broly: The Legendary Super Saiyan" and he got defeated by a strong 5x full-power-SSJ (weakened BTW) punch.
After getting a Zenkai (there's no other explaination) he easily outmatched SSJ2 Gohan but still got defeated by 3x full-power SSJ Kamehameha, but only because trunks prevented Broly from pushing his attack further.
To tell you the truth, I don't believe that SSJ2 Goku could take "Second Coming's" Broly alone. Vegeta's self-destruct attack, seen in his attempt to destroy Majin Buu, might just do the trick though.
LSSJ isnt a form, its an identity. Broly is a very unique saiyajin in that he had this overwhelming, seemingly infinite pool of ki at his disposal. What we call LSSJ is simply Broly tapping into that large reservoir. Its not merely a glorified USSJ transformation, because Broly is unique as a saiyajin, and in his ki, not to mention a lot experience in using it.
Youve also got to understand how his mental instability and one track mind compound his destructive power as a saiyajin. I believe an SSj2 would put up a fight against Broly, but his whole sense of character trumps basing assertions on mere powerlevel differences, almost how the character traits of Goku make the powerlevel of his opponents unnecessary.
I may be wrong, but I always associated the green aura with Brolys natural ki, not because of the control device. The device merely inherited that colour because it was channelling and constraining his ki to begin with.
Yes, Broly, the legendary super saiyan, has an unique form. It doesn't really have a name, so we simply call it LSSJ since only the legendary one can achieve it.
I have always thought that Broly LSSJ form's color is not golden, but lime green. Until I got a-make-sense explaination why he didn't have that color in his second appearance in "Broly: Second Coming". Anyway it's true that Broly has some kind of green color, but not in aura or hair.
The control device gave Broly some kind of violet-blue color while in SSJ form since it still controlled him in some way. Once Broly got out of Paragus' control, the color went lighter - lime green. That may be because he still had a device part on his chest or/and maybe that green color still left around him for some time after he got out of the control. I doubt if it is ever gonna be explained so let's leave this part as it is.