Thousands of people play Arma2/OA/CO on a daily basis, you're the first one brave enough complaining on a FREE game. Best and easiest solution to fix it is to buy ArmA 2 (I suggest add Arrowhead).
No, I'm not a reseller, not a PR machine or a game-pusher, but if you want smooth gameplay (or help with it), most of us can only give advice on full game.
Beside that, Arma2 FREE
IS what it says to be, it's a free version of the
*payed* Arma 2 military simulator (still not a game).
I can almost promise you; if you buy Arma 2 OA, Arma 3 will be out one day earlier

(of course totally off-topic and not approved by any serious military simulator developer)
BTT:
A free game have limitations, how can you (or in this case BIS) get their money back if they give away the full game?