Keep in mind that if you're next to each other in Initiative count, you can switch attack order if you want. If you post more or less simultaneously, I'll follow the "official" Initiative order and allow whoever goes second to change his action if something relevant happens (e.g.: the first guy kills the second guy's target).
Additionally, remember that you have 24h before I allow other players to control your character and 48h before I simply skip your turn. Similarly, if I don't post a creature's actions for 48h, you are allowed to consider I skipped its turn.
Last, but not least.. If I have to allow others to control your character or skip your turn twice in a row, I'll start allowing other players to decide your character's actions as soon as your turn comes up for the rest of the combat. I'll still wait 48h before skipping your turn, though.