I only recently read the book about the famous Fokker E.III pilot Max Immelmann,
and he went up mostly alone. Sometimes he "found Boelcke" on his patrols, but I
found no such thing like flying in a formation.
My advice for all new OFF flyers: drop the idea of flying the war chronologically
from the beginning (and if the pilot dies, starting again) - enlist pilots in
early and later 1917, and in early and later 1918, just for testing and checking
out, how much there will come in OFF - you could be missing the most of OFF,
if you try to get there by surviving all those months - most likely you won't.
At least I could never achieve that yet.
As for the flight path, you can click "Optional flight" repeatedly in the briefing window,
to get a path of your likes. I did not find a difference between the briefing course and
the path in the inflight map. That may result from using the mod.