Be very careful quoting FARs as far as load factors are concerned.
They are design requirements, and probably haven't been demonstrated as such - for example, there is a requirement to design for a full pedal displacement at cruise speed, but no-one I know of has ever demonstrated it.
And there is a major concern with negative G - as far as I know the hydraulic tanks are not pressurized. At zero G, you're likely to not have any hydraulics going into the pump...
(happened to an HH-65 at the US Navy Test Pilot School when I was there, and I don't think the AS-350 series has much difference in hydraulic tank design).
So be very, very careful when thinking about doing any negative or even zero G stuff - in any helicopter.