Finished once? This aint a game you finish. Have you tried the sp editor and the Mp editor?I bought ArmA 2 OA today, and I already had ArmA 2 on my computer (finished once, having another crack at it).
Youll never finish anything once you get into building your own stuff.
If you ever need help with the editor at least with knowing the basics, then give me a shout,
or ask some of the guys on the forums here, theres plenty of them that "only" play in the editor. Sp game whats that?, lol