Outside of quests, in general it's actually not so hard...to get to Elah at least. Because there are no forced uniforms or markers of any kind to differentiate between the two, Corsairs could just pose as travelers or tourists to visit Elah and that would be their in. Maybe have some false IDs to get through any security checks, but I mean Corsairs. If they can't forge documents they need to be shamed. The same would have worked for Paladins, but Nogard by its nature is more secretive and tries to keep its location away from the Paladins.

So for the Paladins, posing as a Corsair or finding a merchant vessel that does trade with them would work! They would have to be very good at posing as a Corsair, however, or they may get caught and jeered at. To be honest, Corsairs would probably be both impressed and frustrated a Paladin got in. Impressed because wow, that goody two shoes manages to sneak past us!! And frustrated because wow, that good two shoes managed to sneak past us!!!!!

Hope that helps!