I believe the FDE is based on the default EH101, certainly the air file does not have the helo sections in that the 206 has, thus ( In my very humble opinion ) making it a very difficult style of FDE to set up. Theres basically two types of FS FDE, one where the air file holds all the rotor and lift drag information and one where 'some' of that info is added in as extra to the cfg, the former is the older set up and requires air file editing, the later is the new style which should make it easier for 3rd parties to edit, ie all in the cfg and only requiring notepad or word pad.
There does appear to be some nasties in there, I was sent the FDE (pasted into my beta model here) by a very desperate customer to see if I could tune it to be more stable like the Alphasim CH-53 etc, I couldn't, it is a real hand full, yet some seem to be flying it ok ?. Theres an uncontrolled roll to the left, the tanks are all different sizes which also gives an abnormal tilt one way to begin with, this may be true to real life (I doubt that some how) but these are the sort of things you need to fudge to get a FS FDE to work respectably, tank capacities and locations need careful mapping to preserve the CoG and balance. It is also incredibly nose heavy, almost 50 deg nose down to build up speed, the default EH101 does that too and any sort of rapid nose up climb or sharp turn bleeds speed and as noted above cause's engine failures, now this may be true to life, but I suspect most here just want to fly

.
When I return from the states mid next month I'll be making him up an old school replacement FDE that has the helo sections in the air file, he'll then test that with the model to make sure all the gauge's and sounds still perform correctly.
If your having problems with the Puma then try the default EH101, you may well find you have the same or similar problems there.
I'm not casting judgment on the Puma FDE, its manageable but I (and this is my own personal view) think it could have been so much more, why its behaving like this I do not know, I'd love to find out what it is thats creating these odd forces, certainly on my set up and I suspect a few others, truth is, it's easier (for me) to take my stock heavy turbine file, cut and paste the headers, tanks, lights, gear and cameras and tweak to suit.
Best
Michael
Addendum, before anyone cries thief or pirate due to cfg and air file swapping, be aware the customer sent them to me in desperation as he was getting no official support and has a product totally un usable to him, I'm only trying to help.