Yay! I got a reply
I like the idea of where you have to persuade other planets to join the empire.
Hmmm, you are the second person who liked that part. No, it would not be a minigame, just some politics/economy/diplomacy/culture thing. Maybe some negotiations (like we will join if we get special rights, exempt from taxes for 100 years and everyone else is the empire is declared our slaves
) Or just slowly being exposed the the culture of the empoire and to our merchants so the number of population that supports imperial ideas grows and one day the planetary government says they want to join.
Or we could just send our superior imperial fleet and conquer them if we got tired of waiting
Resources/products - yes... it might fit here.
Campaign - well, you could say it's the explanation of a campaign, but I was more thinking that the whole game is like that (like you get it similar eacxh game, just different placement of planets and big events at different times from diferent points of the map and maybe some excluded). I don't know, I was not thinking about the campaign part too much. But 4X games in general do not have any campaign thing just different settings to "generation of the galaxy"?