We just used the level adjustment playing as a monster rules in the mm and regular PC classes iirc. A big part of getting the roleplay to work out lies in setting the scene for the right mindset. If the PCs have trouble telling one prey-villager from another without scale patterns or whatever (they did!) maybe just introduce them by their clothing or something. Describe important details like the ingestible marinades (food and drink) without mentioning extraneous details like what would normally be described when visiting the mayor since there aren't many buildings in town with a room that can hold a whole party of hatchlings. Don't worry about getting them to the mayor when obviously the jeweler or blacksmith is the real power here going by their hoard size... Sure those people might be in the room advising their alpha, but it would be extremely rude to ignore the prey-leader in order to acknowledge hearing or talk directly to such a lowly servantIt's cool. Before 4e, Dragon Magazine had two articles where you could play a Dragon PC as though they were a class. One article covered the Chromatic Dragons, the other covered the Metallic Dragons. Each Chromatic and Metallic Dragon had their own class, and each class was designed to cover the first four age categories (Wyrmling to Very Young, I believe).
I like how your party role-played things from a draconic point of view.
It's an extreme example, but the more culturally twisted that the mundane goes through in description really changes how the players interact with it... Take humans and some primates... Nearly every species in earth bears their teeth as a sign of threat/aggression... Except the ones that do it to signal things like joy humor and friendship.