You can play all campaigns and missions which require Arma 2: Operation arrowhead with or without BAF and/or PMC.
If a mission or campaign requires Arma 2 than you can not play it.
The same goes for addons and mods.
You can find the Arma 2: Operation Arrowhead download section here:
- Arma 2: Operation Arrowhead files
All files there you can use, except those which depend on Arma 2. Also it is possible files depend on other addons which in turn depend on Arma 2. But, there is more than enough stuff available without needing Arma 2 (for starters at least).