Regarding the map download.
I always hold my mission briefs 15 minutes prior to launch.  By making this SOP in my squad, it guarantees they get past the long downloads.  
As an operational planner and a lead in my squad, I jump in an hour before launch.  If there was a download I thought may effect my squad, I let them know to come earlier.  It is a check and balance I learned from before.  Nothing anyone can do about the length it may take to download a map.  
Take some initiative and check it out so your squad is ready.  Nobody's fault but your own if you can't be in the arena on time.  
That is a CO responsibility...