I will find a place to host my missions for both multiplayer and singleplayer that are 100% for Arma 2 Free. I currently have one that is stage 1 complete, meaning its working as intended with all functions, and works in both modes. I will expand upon the mission for multiplayer since its very tough to complete solo. Here are a few of my ready to upload maps for multi.
Sniper School, Target range on Utes with a squad of infantry to kill once done.
Basic Training, Utes scripted multiplayer for 1-3 players. Has AI taxi setup.
Reverse Red Dawn, Lots of scripted transports, Lots of enemy, random action.
Other MP missions I have downloaded and are 100% working on Arma 2 Free.
28 Days Later, Cheap DayZ knockoff with less features and for me laggy.
Survival of Chernarus, Works well, lots of random loot crates, bots for SP play.
MP Warfare, works but not sure what Im doing, base spawned in way out of the way location.
Dynamic Zombie Sandbox (latest version) it freezes on loading at DZS splash screen, but others say it works.
Please feel free to add more and I will update with links as needed for the ones I didnt create and will upload mine later as well.