Gustavus Survives the battle of Lutzen what happens next does Sweden manage to take over the HRE and Gustavus becomes the Holy Roman Emperor as he wished to do, does he become to the controller of the Baltic
yea i read something along those lines but i could see him doing that if he wasn't so aggressive in his battles maybe a split between the two with northern germany being protected by Adolphus and the southern area being controlled by the habsburgsGustav did not want to become Holy Roman Emperor, as that title was way too catholic at the time. More likely, he'd create a new title, such as "Protector of Germany".
Aside from that, all you said is plausible, concerning the time frame upon which we can speculate.