I believe that implementing a National Park will have to be on a smaller scale. It is going to be too difficult to implement a pretty much modified Safari Zone. I know it would be a cool idea but it should be scaled down so that it would be easier to manage.
As for the NPCs or TRPG idea.
Using a random generator takes both the skill and strategy away from a battle. RPG would make the battle like that of you verses a wild pokemon in a game. I understand how your trying to found the idea, but I don't think we can implicate it in the way you want. Maybe set up a tutoring system, where older members can help younger member with strategy by assisting them in a battle.