yes you can, because goten and trunks fused and became gotenks
Yes, Dragon Ball GT.
no there will be no more dragon ball z but may be more sagas
Dragon Ball Z Sagas - 2005 VG was released on: USA: 22 March 2005
yes
Dragon Ball Z: Fusion Reborn (the 12th movie)
According to Dragon Ball Wiki, no. But I have played Dragon Ball Z: Budokai 2, and you can unlock him there by wishing for the fusion from Shenron.
you can't. DBZ Sagas only goes up to the Cell Games Saga.
Season 5 Sagas: Imperfect Cell - Perfect Cell - Cell Games Season 6 Sagas: Great Saiyaman - World Tournament - Babidi Season 7 Sagas: Majin Buu - Fusion - Kid Buu The End
babidi and majin buu
Play the game 5 times completely
beat all the other sagas
Two short sagas, actually. Perfect and Imperfect Cell sagas of 26 episodes.