I'm not sure which game you're talking about, but corruption was never present in Civ4 (actually the whole point of the revised maintenance system was to replace the heavily criticized corruption mechanic of Civ3). Cities built far away from the capital weren't useless in Civ4 because you could develop them normally as long as your other cities produced enough gold to pay the maintenance, whereas cities built far away from the capital in Civ3 were completely useless because the corruption mechanic limited them to one shield and one trade, you had to buy every single building for them but there wasn't even a point in doing that because what's the point in paying maintenance for a building that provides a 50% bonus to a production of one trade. I'm also pretty sure that you could group units by shift-clicking on them since day one, although I'm not entirely sure on that one since moving single units around never was a problem for me.