Naval GLs might help to influence people to use more of a navy in the game than currently exists. Noone uses a real navy much.
GLs founding a city, sure. But your suggested city is too much.
GLs for a tech, maybe. It seems like it'd be a little unbalancing in some types of games.
Of course, there's the whole question of peaceful GLs. They've been suggested a zillion times before, and I agree. GLs for certain goals that aren't militaristic would be great. Refer yourself to older threads for what goals they are.