If you don't like the idea of coding all this from scratch, there's is a much better method using Stuart's checklist system - you'll basically convert checklists into XML, which in turn can be "executed" by FlightGear for each step of the checklist:
http://wiki.flightgear.org/Aircraft_ChecklistsIdeally, all aircraft should adopt this system over time - and if anything is missing, the checklists system (100% scripted) should be extended.
The good thing here is that this turns code into data, so that we can easily unify this for all aircraft to come up with a flexible system, without having to maintain possibly hundreds of different startup systems - especially keeping in mind that many aircraft are no longer maintained, and that the quality of Nasal code in aircraft is generally not overly impressive.
The data/XML-based approach has the added advantage that the Nasal code can be maintained by a few peope who are very familiar with Nasal, without them having to be experts in each and every aircraft - while aircraft developers no longer need to be proficient in Nasal and no longer need to know how to write Nasal code that behaves properly in all situations (think reset/re-init or reposition).
Having custom-scripted startup/autostart systems is not a good idea - especially because we want to support other use-cases, such as for example in-air starts, e.g. for flying approaches over and over again - an XML-based checklist can be easily executed, and it can even be used to set up the cockpit to some predefined state.