They go there automatically, it's split between the governed cities. I just had the thought, maybe on the turn before you take a settlement, you can take the governor out of the cities that you don't want population added to, and then use enslave after the battle, and then put the governors back in. Maybe that's a common strategy and I'm just slow ;) , but it sounds like it'll work.

As for loyalty over 100%, I try to keep it at ~125%, just because loyalty seems to decay somewhat as time goes on. It gives me a bit of a buffer zone.

@Mariux Maxentius: It's a good idea to spread your troop building around a bit, and not just focus on the capital. Since you have Sicily, that's a great place to build up troops. Two cities can focus on them, along with Capua, and then the other can build a navy. I used to play it your way (granted I've only used Brutii so far), but my troops get built in Tartenum and Croton, my two Italian cities, as well as Salona, and I build ships in Greece (Athens). I can get a good, balanced army in about 7 turns. Once you grow you can do this in two areas, and then you'll be very powerful.