More secondary objectives would be ace for this game; implementing command posts would be a nice secondary objective to have in the game as long as it gives a substantial amount of power to fight over.
I would suggest a buff to whomever controls the CP; 10-20% cooldown to their active abilities. This would give the team that much more up time to their actives and an incentive to controlling it.
The placement of CPs should be in neutral territories where each team could vie for it at all points of the map (or at least accessible during the final half of the map). Otherwise it would be considered a permanent buff with very little control over who would have access to it. C4 would be the only way to destroy it to ensure that the team has control over the CP for a period of time.
This would create a secondary objective where teams will have a team member or two at for periods of time and creating more active areas.