Hey there!
First of all, you might want to check out the Second Edition forum, as this is the old first ed section.
But, onto your questions:
Robert's STR changes encompass all characters in play.
They take effect immediately depending on who stands or kneels.
However, the STR requirement for The Kraken's Grasp only applies when the event is first played. Once the lasting effect is applied, it doesn't cancel the effect if he gains more STR.

Almost looks like you answered your own question.
 
But no, all secondaries ignore the standard bonus to attack or target's defense depending on range.  Other things can still apply of course.

Nope. ANY secondary weapon denies both the R1 red dice bonus and the R3 green dice bonus. 

That could be mould release agents messing with the paint, since the surface is not meant to be painted they won't take it off. Give them a good scrub in detergent laden water, and let then dry and you might find a better binding. Or lightly sand the surface with T-cut or similar to let the paint bind, perhaps.

You're making the argument that this game currently exists in the only state of balance that is possible.  But why is that necessarily the case?

Indeed and that's where I start out with this sort of thing. However, no matter how useful said aphorism is as a start place, I have been burned on doing just that in too many games only to find out there is a ruling going the other way for something due to some convoluted track. Also, the subtle differences between US and UK English mean there can always arise arguments over what the card says. Fortunately, this one has turned out simple in this case.

Yes, it's a huge triumph to know that the situation that would likely never occur is resolved the way everybody knew it should be.

So I worked like a dog on these and got them done in two weeks (of course, I haven't had time to try the game as a result).  I'm happy to post if it helps give people inspiration, and feel free to ask any questions you might have.  For 150+ miniatures, these went fast since they are so small and most of them just required a base coat-dry brush-wash-a few details.  The rebel troopers took the longest.  Sorry in advance for the non-optimal photo quality, as I only have a cell phone camera to work with and wanted to try to fit everything into a handful of photos.
 

They do not participate in that mission.

Do what the card says, not what you *think* the card could/should/would say.

And above all, have fun!

Any ship except Huge ones, which are limited to "Huge ship only" modifications.

Correct, any ship can take shield upgrade. If an upgrade has a limitation, it is always clearly stated on the card.

No, I don't think they can. Like you say, they only join in when the mission card says to play it against them...

there are no scum yt freighters. the jumpmaster has filled any possible gameplay function that the yt could and much much more

When playing a 3 faction game, I have typically been the scum. To add interest to the game, I come in 1 ship at a time for the first several turns starting with the highest pilot skill. I roll a die to determine which side of the board to come in on. It makes things interesting, and sometimes short lived for me, but fun.

I've played a three faction battle before. Only thing different is setup: one player sets up in bottom left corner, another in bottom right corner and the third player sets up at the top of the board in the middle.

No, boost and barrel roll cannot normally overlap asteroids; if the token or ship would overlap, the action fails.
 
The (soon-to-be) exception is Tractor Beams, and we don't yet know how they work fully WRT asteroid damage and effects.

There is sort of an element of that in Red and Green manoeuvres and their overall effects - Red it and you lose an action that means you evade less well (ultimately less power to shields if a little abstracted into manoeuvre terminology) and when stressed, a Green gets an action back for many so going slowly gets more accurate firepower and/or defense (lasers or shields abstractly) if you use that action to pop a focus that you would have if you remained stressed
 
Even the focus action itself is partly a controlled balancing of firepower vs shields/speed defences in some ways.
 
So I think it is there. I would not want to see any ship just being able to take actions of this type though - there is such a thing as too many options being slapped out to everyone. I mean there are near half a dozen standard actions and ships can take 2-4 of them which makes for a perceived variety that is quite high If you added 6 more than everyone can do then you get ships doing 8-10 out of 11-12 available which is less proportional loss of ability.
 
There's nothing to say they couldn't come into the game in some form - but I would rather see it as an upgrade card of some kind. Flexibility does have a value after all. That way you can add the ideas to the game but not swamp it with too many extraneous actions or playing with the balance  of actions as you are simply adding another slot. We do have to think about balance as well - we already have such a card in the game in R2D2 where you trade speed for shields. So how many others exist that simulate the idea looked for already and how much would it alter the balance of the game to introduce more options that do this either as a generally available card option or even more so a generally available action option. If you have an Xwing with R2D2 and could add another card that gave more shield back on a green how would that affect things - even if it was made an action unlike the automatic effect of R2D2.
 
So yes, nice idea with some potential but there are many elements - kind of - in-game so any introduction needs care if it becomes generally available.