Their main 'external' threat was as it ever is in the periphery.. pirate predation.
Politically, they attempted to please both neighboring great houses without offending either one all while remaining too insignificant to warrant undue attention.
IIRC there was a plot in the 3025 era to marry an Avellar daughter into a FedSuns noble house, complicated by the apparent alliance with Davion drawing Kurita retaliation. Obviously, never panned out.