I was talking to one of the developers who created the aircraft models for the sim quite a bit after its launch, through my role at simFlight, and he was saying that all the modelling he did was through the SDK for the other package sold by the same company, simulating radio controlled aircraft rather than first person view.
You can certainly see the RC roots of the sim when you watch the "crash testing" video that was created of it (http://www.simflight.com/2012/01/07/aer ... h-testing/
) but that does mean that even if they haven't released a formal SDK for AeroflyFS yet, there are tools available to create for it. However that same genesis of the RC sim presumably is why there is no systems depth yet - you don't tend to need to change altimeter pressure settings on an RC aircraft, nor do you tend to really need to receive VOR, NDB or ATC signals.
As I said, I don't have it so cannot say specifically what is and isn't already present - you might be better to Google reviews of it for that (Google translation of simFlight.de's here: http://translate.google.com/translate?s ... -ikarus%2F
) but I do understand that most of the technical requirements are not present in the sim yet, rather than just not being in the aircraft panels, so they would need adding before much else was. I also don't know if there is even an ability to read from an external application in the way that the MSFS series can using FSUIPC or now Simconnect. That would be required before something like Accu-Sim could be done.
AeroflyFS is certainly not a "full blown" sim yet. It's still very much in its infancy and I, certainly, don't know where it will be expanding or, for that matter, if it will be expanding. They may be happy with what they have already.