hleV, you like Broly, that is OK, but I'm going to tell you something:
Gohan NEVER, EVER mastered SSJ2. He was all 7 years without doing ANYTHING, being lazy.
Toei can say whatever they want. Is like an exam, you put 2+2=5, is bad, is not correct, and you tell the teacher "No, I meant 4, so is OK". No, is not OK, you did it bad. The same happends with Gohan in that movie. the only way to distinguise betwen SSJ and SSJ2 in that Gohan is electric sparks. No sparks, no SSJ2. Broly was toying with Gohan, that is the cause he didn't kill him ina punch, but that doesn't mean Gohan is stronger, just Broly lowered his power to not kill him and have more fun.
Now, I'm going to leave that off-topic because you aren't going to change my opinion and me neither yours.
I prefeer Vegeta going SSJ3, but is still not possible. SSJ3 is only obtainable being dead or fusing.