Well I've been following this debate and I have decided to add my opinion to the mix.
When riding in the APC, troops expend actions as if they were part of the crew. Just as you cannot drive, drive, drive and then shoot, shoot, shoot you cannot deploy out of the actions sequence of the vehicle. Basically the vehicle is a unit and the crew are symbiotic components that make the whole function. The basic question is using actions so the best place to get the answer is in the section on using actions.
The rule is stated clearly and in simple terms on page 40, first column, first paragraph of the Vehicles and Using Actions section - In general, when a vehicle is activated, any crew riding within it must expend their actions simultaneously. If the driver uses his first action to drive, any other crewman must spend their first action before the driver can spend his second. If the driver spends his second action before the crew takes their first the unspent actions are are lost, unless a Special Ability declares otherwise. That covers the rules citations in my opinion. As for rewriting the rules just because you don't like them I find it short-sighted with regard to game balance. If troops are allowed to disembark at will with all their actions then the transport becomes overly powerful for it's points. Warzone becomes a vehicle-centric game and the tactics are lost.
Tactically the APC is best used when the driver takes his first action, then the gunner attacks the strongest opponent within firing guidelines and then the troops disembark. Now the Troops use action 2 to move to cover, the gunner fires and the driver puts the vehicle between the troops and harms way. The final action is similar to the second. Optionally the driver always goes first and the troops follow behind using the APC for cover much as the troops in WWII used tanks. Using the APC as a shield allows the troops to move forward under cover and yet break at any point of the turn without getting stuck in a disembarking bottleneck.
The FAQ Team in my opinion is there to correct ambiguity in the rules not to redesign the rules someone dislikes. That being said no one here is held to the FAQ Team's interpretation, my interpretation or anyone elses when playing a simple game with your group. Just come to an agreement beforehand. However if you are playing at a Con or special event respect the ruling of the event organizer or judge. Arguing a point with the guy running the event is pointless and ruins the fun for all the players. If you disagree with something state your objection calmly and abide by his decsion.
In closing the rules in this instance are pretty clear in my opinion. Instead of changing them to fit your tactics try working with them as written and you might discover some new and inventive ways to use the APC in the game.