Short answers, pulled from the story.
Generalfeldmarschall Maximilian von Weichs assumed command of Army Group F on the 12th of August 1943. Lieutenant General Hermann Foertsch served as his Chief of Staff from that moment forward.
Army Group F was established at Bayreuth within the WK XIII district. The unit operated primarily across the Balkans region to counter Allied threats through Greece and Yugoslavia.
Army Group Serbia formed on the 26th of September 1944 to defend Serbia specifically. General Hans Felber commanded this detachment during its brief existence before disbanding on the 27th of October 1944.
Collaborationist foreign volunteer units including Cossack forces joined the ranks by July 1944. Helmuth von Pannwitz took command of XV SS Cossack Cavalry Corps starting in September 1944 while the 392nd Croatian Infantry Division operated alongside regular German formations.
The official dissolution of Army Group F occurred on the 25th of March 1945. This date marked the end of its operational history within World War II after a major withdrawal from Greece and most of Yugoslavia in late 1944.