Hey its ok for a starting position, I'd defo swap for a ubacs though or when it starts to get a bit chilly go for a smock. As for the Molle carrier, yer just flesh it out a bit and try using a cut up roll mat for padding. work wonders and keeps its shape. Whilst there are standardised positions for all your kit it is common practice to swap around to your personal preference, within practical limits obviously (after all if your in theatre you use whats best for you).
Here is a pic of my co-driver in Basra. I know its not Afghan but I've only got pics from Iraq as I've never been to Afghan.
Oh and the left handed firing, big no no. Even if your left handed you still fire the L85 from the right shoulder unless you want your eye taken out by the cocking handle. I know its not relevant for airsoft but just for the look and don't got forget to cock your weapon with your left hand