So what did you do with Henselt at the end of Act 2? Did you spare him or leave him to Roche?
On one hand I think he should pay for raping Ves and murdering Roche's people. On the other hand, I don't know if I want to contribute to the killing of a king. This would make me as bad as that Kingslayer lol.
Thoughts?

How big of an impact on Act 3 does this decision have?.

I let Roche kill him ^^ It doesn't have even a slight impact on chapter 3.

Regicide isn't that bad. Besides, you're not technically the one doing it--just engaging in some hardcore Witcher neutrality by not stopping Roche. Yay neutrality!

I played only once on Roche's side and I immediately let him kill Henselt without feeling any sense of guilty. He was a weak king and a bastard, besides, he collaborated with Nilfgaard during the previous invasion, so I doubt letting him live would be beneficial for Northern Kingdoms.
In general, almost all of kings in W2 deserved to die, except Foltest.

I always have to think long and hard about these decisions.
Anyway I can't let that son of a b**** live. That b***** rapes women. Yep he deserves to die.
Decision made then lol.

it might not have any impact on how you play through ch3 but i assume that it certainly does have a LOT of impact on events in witcher universe.

Firstly, there was no one to represent Kaedwin in Loc Muine during the conclave and their camp was said to be in disarray. On the other hand if you let him live, he is present during the discussions boasting of his victory and trying to divide Temeria with Radovid.

Secondly, consider for a moment the state of kaedwani court if you kill henselt - they've just won the Pontar valley and ther's no king and he's left no heir either. I mean killing henselt leaves kaedwin in even a worst state than Temeria , atleast Foltest had left two possible heirs even if they both are too young and one of them gets killed.

I meat there is no impact on gameplay ^^ ofc there is a huge impact on the kingdoms...

oh well all I thought about was his bad deeds. He doesn't deserve to be king. He's a murderer and rapist. He's not really a fine example of a noble king.

Yeah, murderer and rapist like any real king in history. Is Foltest any better really? There are and were no "good" kings (who actually had power, modern kings without real power don't count) in modern terms of humanity, period. But, that doesn't mean that anarchy is better. And he "deserves" to be a king like every other king: the might is right. I, personally, let the son of a bitch live but not because I like him.

noble king !! lolz, you would be hard pressed to find one in the witcher world. Foltest was the only one who i believe was the closest to being one and even he wasn't perfect .
I really liked him though , Damn why did they have to kill him, they could picked Radovid or any other idiot , who cares..

I let him live, and am glad of it. Now, instead of Redania against Nilfgard, its two strong kingdoms allied together. I kinda abandoned Temeria, since Geralt doesn't really have a nationality, and I wanted the northern kingdoms to survive.

I also saved Sile, and pardoned Letho.

whoops, fixed. It seems that they had thought up the plot of TW2 while they were still making modules for TW1, since there is one with Sabrina in it.

I let him live on my play throughs, but i also helped roche to save Temeria 'cause i felt a certain bit of loyalty towards Temeria mainly due to Foltest and Roche even though i know as a witcher i'm supposed to be neutral, i just couldnt abandon Roche and go running after Triss after staying at his side for the whole game.

Bros over ho's !! cheers

According to the Witcher-Wiki (I didn't play it myself, yet) "Price of Neutrality" takes place even before the books - so there's no inconsistencies there (although Price of Neutrality was inconsistent with the books, as they meet for the first time on Thanedd during the books' story).