Because its a free roam gamemode, will we be able to follow random people's adventure? I require an answer before I play the upcoming beta. [spoiler][b]I AM A GOD[/b][/spoiler]
If they stay in the free area then yes, if they join a fire team only mission or leave the social "bubble" that you are currently in, you won't be able to follow them.
I'm quite sure ya have to be in a fire team to actually share the random missions you find.
Yes you will be able to join in on random peoples games if they have it enabled. As far as I know