Taking the rest of Greece would be a profitable venture, but then you have to worry about spreading your forces thinner as you'd have more potential enemies around - Thrace, Germans, Dacia etc so you end up producing more troops to deal with any incursions into your land. I'd make inroads towards Greece, but at the same time try to secure Gaul and Iberia. If you secure the western borders, you only need to keep small garrisons there to protect from rebels, then you can concentrate your forces elsewhere - ie: Italy and the eastern frontier.

It's good you got a foothold in Africa in my opinion, although it's a pity you hadn't managed to take Carthage before the Scipii. If you move into Iberia, you should secure the other N. African provence next to the one you already captured. There's not a great deal of money to be made from that provence alone, but you'll control much of the sea trade in the area which isn't too bad, and at some stage you'll probably end up needing to ferry troops across the sea to Africa. Also hire every single Numidian Cavalry mercenary troop if you're staying in Africa. They're excellent cost effective troops.

Also try to scupper the Brutii advance as much as possible. You don't want another Roman family gaining the rich Greek lands, so any chance you get to capture a settlement that has been stripped of its defenders thanks to the Brutii's earlier involvement, then take it. Finally, don't forget to use forts to slow down the AI advance when you're find yourself weak of soldiers in a particular area. A single peasant unit in a fort blocking a road can give you a couple of turns to get reinforcements from elsewhere. That way you don't necessarily need a massive garrison in every town because the forts give you extra time to move men around.