I am taking a look at the save now; this may be a bit stream-of-consciousness.
I think Rome is a good target, Legions notwithstanding. Note the tiny town of Pisae in the ocean to the west of the Hittites (southeast quadrant of the map). That means we can comfortably raze all Roman cities and replace them ourselves.
I'd also like to see us take Persia, for two reasons: first, they already have a city off their island (Bactra), so we can clear it with impunity. Second, with all the coastal tiles around it, it will bring in some useful domination numbers for us. Unfortunately, Immortals will be a royal pain in the butt.
Really, though, I think we need to focus on the big prize, which is the island that has Germany, Greece, and the Mongols. That is a sizable island, with a number of useful jumping-off points to neighboring islands should we need them. We should be prepared to run roughshod over that island. The Iroquois should provide a useful gathering point for forces, if we want to go that way.
My general plan at this point would be:
1. Continue war vs. Rome, since we're there and may as well finish it.
2. A short war with Korea. Korea makes for an IDEAL jail site, and I have an idea as to how to pack a number of cities in there for civilizations that we are otherwise "done" with (see dotmap).
I believe that we can use cheap units (scouts) to fill in the spaces between the cities on this peninsula. This should totally prevent any AI vs. AI combat unless they are also at war with us. And, assuming we can browbeat them into a right of passage (or at least staying away from war with us), we may be able to fill those spaces more or less indefinitely.
The basic plan would be:
-Raze Nampo
-Settle red dots ASAP
-Gift red dot 1 to a civ (e.g. Ottomans, Germany, Mongols, Greece, maybe America?).
-Remove all other cities they have
-Make peace with them, finally and for all time
-Move on to the next civ
We would require a few defensive units (not many) and a few scouts to prevent any further expansion or movement.