then get sixupdater and download JSRS and Blastcore and play all those mission again, it will be like playing a new game. Get some buddies near your area and host insurgency server on your PC. Download those missions in armaholic, there's a lot of it. After a few months start playing with ACE, then later on start playing with the editor and all those user made island.
Since you havent tried OA yet, there's a lot more cool stuffs in OA. I'm sure you also havent tried the PMC minigun SUV =P
Amazon offer still up, get it while it lasts. Or if you have the cash, get arma X bundle. OFP campaign is a great game for training AI command XD