Consider enlisting a party caller/leader. This individual should be in charge of the initiative tracker, status condition monitering, etc.
I would also impose a table rule that says that anyone who catches a major error (missed status condition, etc) receives some sort of reward. An extra AP might be too much, but something significant enough that self-policing is rewarded and encouraged (perhaps a consumable item of the appropriate level).
Finally, I would consider enlisting one player as a tracker of monstrous status conditions.
Between those three measures, tracking bookkeeping status should be greatly eased.
As far as fights go, large open spaces are good. However, consider some small cramped corridors that prevent the party from easily deploying to unleash their full strength. A few soldier monsters might be able to hold a narrow front for some time. This would best be combined with some sort of trick or trap that makes the ticking clock important.
For example, you could have a narrow gateway that controls access to strategic ground. At the start of the encounter, a weak enemy force holds the narrow gateway while the bulk of the enemy races from a far distance (3-4 rounds, at least) to reach the strategic ground. Can the PCs break through the gate fast enough to seize the ground themselves? If they take their time, then they will face a much more difficult encounter.
The opposite can also be true. In a wide open space, you can use a few skirmisher monsters to force the party to deploy widely. This might kill time and delay the party on their way to some more important tactical objective.
