: What's it like using the hog?

Pretty good. It feels the same as it always has really, however there's only one section in the game where it's available to you, so make the best of it.

: If you are shooting the gun do they take the wheel and drive you - away from
: the action?over a cliff? up against a rock to stick on it? nowhere
: particularly sensible or strategic?

Well you can still press up on the d-pad and direct the AI driver, however I tended to find that they would drive towards the action and circle at a distance. It was pretty good. Riding passanger on a Gungoose though is a lot more risky, as the AI seems to drive it like a Warthog so it flips and gets stuck A LOT.

: Can you tell them where to drive? To stop?

Only where to drive too. You can't tell them to stop. In general the team commands are really limited and a stop/regroup one would've been awesome. Oddly the characters have dialogue for this order which they call out, but it doesn't actually do anything and you can't control it.

: Did you try the changing seats mechanism? What was it like?

It sucks, but it's useful if your alone I guess. Changing seats makes the AI driver/gunner get out entirely, and they have a pause of several seconds once your in place before they figure out to get back in, so any advantage you could gain is lost in the lethargy.

: Are AI drivers aware of your shield state?

Not at all.

: Do ally drivers prioritize enemies: well? at all? Do they still shoot
: corpses when deadly threats are near?

They don't shoot corpses but they don't prioritize either. They will shoot crawlers instead of a knight, etc. Luckily you can tell them what to shoot at.

: Did you switch weapons with ally NPCs? Was it easy? Did you have to run after
: them and try to get in front of them to try to get them to stop and then
: switch weapons? What was the experience like?

I didn't try this and I never saw a pop-up for it. As far as I can tell it isn't possible anymore. You can however tell allies to pick up certain weapons on the battlefield. However this basically sucks as well because you can't tell who to pick up or drive what. So if Kelly is in a Scorpion and Linda is on foot, you can point at a Ghost and be sure Kelly will get out of the Scorpion, get on the Ghost and Linda will be none the wiser running passed.

: Was it easy to switch weapons with an ally that was boarded on a vehicle?

See above.

: If you switched weapons with an Ally on a vehicle did they dismount, go to
: the driver seat, and drive away leaving you chasing the vehicle?

No, if anything they would stand by it figuring out what to do.