1) It works for any weapons or unarmed attacks you happen to have. The requirement is that the enemy is Suppressed and does something to provoke the reaction.
The note about ignoring the Unweildy trait is not a requirement of the action as a whole. It is an added bonus that prevents it from failing to work with those Unweildy weapons.
2) The Plated Vesk armor is using Pathfinder-style runes for its upgrades instead of the Starfinder-style equipment grades. It would be best to stick to only one of those two systems. So you can use the Flight Suit for its upgrade slots and environmental protections and such, but ignore all of its other armor stats.
I haven't done the math on how the resulting AC shapes up in comparison to other options. I remember people were moaning about Automaton Reinforced Chassis for similar reasons at one point. I suspect that the game devs value always-on armor more than some of the players do.
3) I'm not seeing a solid rule for this. I might be missing something though. A common principle of the game is that different things that do the same or similar effects shouldn't stack. There is also an SFS note regarding having both Force Field and Shield Block available, for whatever that is worth.
So I would recommend one of two options. Either consider the Force Field effects to be a Duplicate Effect and only allow one of the effects to be active (using Iomedae's Shield would cause the ally's normal Force Field to deactivate and go into its cooldown, for example). Or allow them to take effect sequentially (If the enemy's attack burns through Iomedae's Shield entirely and ends that effect, then it can start working on the Force Field effect until that is also depleted. And then the character can Shield Block after that).
What I don't recommend is having both active and blocking damage according to player's choice so that they can keep both Force Field effects from ending by splitting the damage across them both.
I take it to mean that it DOES work with weapons with the Area trait, despite Area saying "Weapons with this trait can only fire using the Area Fire action."?
That is a good point.
No, it wouldn't work with Area Fire only weapons. Overwatch gives a Strike action as a reaction. The Subordinate Actions rule would prevent replacing the Strike action with the Area Fire action.
Although, considering soldiers are able to make singular attacks with area weapons with their Primary Target feature, I don't think it'd be too broken to allow one to use one for Overwatch. It'd be a houserule for sure, but not a bad one.
Specific trumps general. I see no reason why C shouldn't be allowed to work with an Area weapon if A and B are. Blame Paizo's wording but it's pretty clear to me. The trade off for all of these bonus Strikes is you only damage a single target but expend the same amount of ammunition as your normal Area-Fire.
A) Primary Target (Free Action): "Before you make an area attack with a weapon[...]you can make a ranged Strike as a free action with the same weapon[...]"
B) Punishing Salvo (Action):
Requirements: Your last action this turn was an Area Fire attack
”You make a follow-up Strike against your primary Target using the same weapon[...]This doesn't make a new area attack[...]”
C) Overwatch (Reaction):
Trigger: A suppressed creature within your weapon's first range increment makes a ranged attack or leaves a square during a move action it's using.
”[...]Make a ranged Strike against the triggering creature[...]”
Specific trumps general. I see no reason why C shouldn't be allowed to work with an Area weapon if A and B are.
Yes. Specific rules override general rules. But only when they specifically say so.
Primary Target and Punishing Salvo (which references Primary Target) work because they state that they interact with weapons that use the Area Fire action. They have an override. Their specific rules trump the general rules.
Overwatch doesn't mention Area Fire. It only overrides the Unwieldy trait. Similarity to other actions that do have an override doesn't mean that it itself has the same override.
I also don't think it would be a broken houserule to use. But don't try to say that it isn't a houserule.
They have an override.
Huh? No.
They don't.
Nothing in those abilities explicitly mentions overriding the area trait limitation. They say to "make a Strike." It's obvious that they are MEANT to work with area weapons but by RAW, if Overwatch doesn't, then neither does Primary Target or Punishing Salvo. A trigger is met, the attack takes place. Pretty clear.
The closest is Punishing Salvo saying that it doesn't count as another area attack. Something Primary Target lacks by the way.
So as usual, confusion is caused by Paizo not being able to write even remotely sensibly. *shrug*
Nothing in those abilities explicitly mentions overriding the area trait limitation. They say to "make a Strike."
Changing your bolding to show where the override is listed.
A) Primary Target (Free Action): "Before you make an area attack with a weapon[...]you can make a ranged Strike as a free action with the same weapon[...]"
B) Punishing Salvo (Action):
Requirements: Your last action this turn was an Area Fire attack
”You make a follow-up Strike against your primary Target using the same weapon[...]This doesn't make a new area attack[...]”C) Overwatch (Reaction):
Trigger: A suppressed creature within your weapon's first range increment makes a ranged attack or leaves a square during a move action it's using.
”[...]Make a ranged Strike against the triggering creature[...]”
While you might have an argument that the override in Primary Target and Punishing Salvo that I am pointing to isn't a very explicit override, that doesn't change the fact that Overwatch doesn't have even that weak override.
Overwatch is more similar to Stand Still and Opportune Backstab than it is to Punishing Salvo or Concentrated Shot. Punishing Salvo and Concentrated Shot are damage boosts that cost actions. Overwatch, Reactive Strike, Stand Still, and Opportune Backstab are additional attacks that are done as a reaction.
Stand Still and Opportune Backstab don't have the clause allowing them to work with Unwieldy weapons because Pathfinder doesn't have any Unwieldy weapons. Overwatch needs that override allowing it to work with Unwieldy weapons because Starfinder does have Unwieldy weapons. But that doesn't mean that the ability is intended to be used with Area Fire weapons. Overwatch says nothing at all about being used with the Area Fire action.
As another similar ability, how would you rule on Reactive Strike - can it be used with Area Fire weapons? Why or why not?
*big snip*
As another similar ability, how would you rule on Reactive Strike - can it be used with Area Fire weapons? Why or why not?
Ummm...you mean the reaction that very clearly states, "Make a MELEE Strike"? No, outside of being used as an improvised melee weapon, a ranged weapon cannot be used to make a melee strike, area or not. Just like a character couldn't Kick someone as their Ranged Strike for Overwatch...
Look. Paizo wrote a trigger and a result. The trigger is met so the result happens. End of line. Same reason you can use an Area Weapon with Intimidating Shot, in which you can fire a ranged area weapon (not via Area-Fire) for the effect...because the trigger was met.