It's actually looking pretty good to me. I would decrease the blaster charge time and make it so that it has to be reloaded more often. Two seconds between shots can be quite a long time.
Edited to 50 capacity and second delay in firing. It does fire in 2 shot burst, which is why I originally had a delay implemented. Two second was a bit much though.
There are some three round burst guns that have been approved in the tech boards that fire on a semi auto basis so I don't think the blaster will be a problem.
I'd treat each of the functions that the droid has as "generic" weapons more or less. a blaster arm is a basic blaster arm, not anything special, no "Exceptional range or accuracy, or better than normal ammo capacity. same goes for everything else pretty much.
the main thing is that if you have something built in, having it built in is a characteristic in itself. otherwise to make things simpler you could just carry around weapons like everyone else.
Considering it can be swapped out for a manipulative hand, would that be acceptable? Where the droid can be modified in the field with the proper equipment and such?