Hmmm... "The only time the left stick seems to make the gun fire is when the motor for the bb gun is turned on" Do you mean the switch up in the loaders hatch? That is supposed to turn off the airsoft - safety feature for the kids I guess. So, does that mean that your airsoft issue is resolved?

As for the barrel elevation, as stated previously, pushing the left stick down works both up and down for the barrel - you just have to wait through the cycle. It is also possible if you are hearing the motor turn that the airsoft unit was not properly installed. There is a tab on the back of the airsoft gun that fits into the cam that turns to raise the barrel up and down. If the tab isn't inserted properly the gun won't go up and down. I did this once when putting everything back together. Take it apart and confirm that the cam is turning and then reinstall making sure that that tab is inserted in the opening. Pretty simple set up and you'll see what I mean when you take a peek in there.

Also, when you put it back together, don't forget the spring that sits between the airsoft unit and the top of the turret [this could also be off causing the problem]. The spring keeps downward pressure on the airsoft gun and makes it engage the cam. The spring will probably come off, but you will see a circle on the top of the turret - it just sits [kind of snaps] on that circle. I put a drop of CA on mine to make it a bit easier to put everything back together and prevents it from coming off.