I NEVER had any gate guards tell me my party was too small. They just simply opened the gates.
For the north and east gates there is a conversation check on the number of characters in the party and their level. After asking them to open the gate, did you not have a response saying 'you don't look like you're quite ready to head out', to which you could say 'don't worry, I can take care of myself' or 'on second thought, leave the gate closed for now'?
The gate by the harbour is closed as it is too dangerous, and there are a couple hints along the beach that the opponents there may be tough.
