If I'm reading this correctly, you had a plains hill start plus 3 clams. You moved off the plains hill for a grassland start so you could get access to more hills...but only mined 2 of the 4 hills?
You could have settled in place - had an extra hammer in your city square and still had access to a plains and a grassland hill (apparently all you needed even by 700 AD). By now, that extra hammer in your city tile would have generated another 145 hammers just on its own, not to mention the faster workers and settlers that might have allowed you to settle more quickly and in better locations. With the cultural pressure you're facing, you don't really even have 3 cities as the other two are hardly working any tiles.
With your capital, you really want to think about what's going to put you in the strongest position in the near term, not end game. No need to move to get 4 hills in your BFC if you'll only have food/ cap room to work 2 of them by 700 AD. The more important focus for your capital is how it sets up cities #2, 3, & 4.
You could have settled in place - had an extra hammer in your city square and still had access to a plains and a grassland hill (apparently all you needed even by 700 AD). By now, that extra hammer in your city tile would have generated another 145 hammers just on its own, not to mention the faster workers and settlers that might have allowed you to settle more quickly and in better locations. With the cultural pressure you're facing, you don't really even have 3 cities as the other two are hardly working any tiles.
With your capital, you really want to think about what's going to put you in the strongest position in the near term, not end game. No need to move to get 4 hills in your BFC if you'll only have food/ cap room to work 2 of them by 700 AD. The more important focus for your capital is how it sets up cities #2, 3, & 4.