I am also very curious about how the weapon systems will work. I think the worse what they can do is to standardize the various machines of the different factions so they would work all the same. I hope they wont do that. I really want to see unique game mechanics for the different vehicles.

For example you can hang on the ork trukk and shoot the enemy while riding but you can also get shot at. The big shoota would be controlled by a different player.
In case of the serpent I hope they make it cost much more requisition since it is the STRONGEST troop transport between the trukk and rhino. (unless they make battlewagons and land raiders)
It should have some special ability that while riding in it you get some health back or you gain some kind of focus buff cos you attach yourself to the vehicle's spirit core.
The marine rhino should give a buff like tactical informations so after you disembark you also get some benefit.

Transports should be upgradable so you could get spirit stones and holo fields for your serpent or star engines which would make you move faster. etc.

I think it would be difficult to make the pilot also the shooter in the serpent. I guess we will need a gunner unless they make an upgrade which will allow the vehicle to shoot by itself (spirit stones, or some advanced machine spirit).

My guess is that the driver gets the basic defense weapons, in case of the Serpent it would be linked Shurikencatapult and or Flamer if i remember right.

One thing i want the devs to do is remember that eldar grav tanks can fly, they strike from the clouds pulse lasers and shuriken weapon spitting death into the enemy

I would like that too, but its not likely that gonna happen. Maybe they will do some stuff like it can have a very high "jump over stuff"ability or something like that at max.

MMOTPS. Think planetside 2, as a third person shooter, with elements of darksiders/darksouls, chivalry medieval warfare, and Space Marine.

that isnt even represented in TT...if it is, then barely, in the form of deep striking.

Balances can be kept by granting the same ability to landspeeders and def koptas and this stays true to the lore

Which is mainly balance seeing as theres no reason they can't.

balance

landspeeders?!?!?! FLYING?!?!?! WAT?!?!