I have since finished both versions of chapter 2 and still think I was right in the OP, sort of...

I found the Kedewen side to make more sense as a plot line.

The Witcher is looking for the kingslayer/his girlfriend
He decides to go to the king nearest to where the kingslayer teleported
The king hires the Witcher to get rid of the mist

The Aderin side still makes no sense to me

The Witcher is in town looking for the kingslayer/my girlfriend
He agrees to a bunch of fetch quests to find the kingslayer/lift the curse (not sure how the curse made its way in there)
He and the hot polish girl are defending the walls of helms deep from Kedwen

The second one is worse but they both are lacking in good motivation. In both cases why doesn't he just find a different place to cross the river?

(if you paid attention during dialogue and cutscenes it would)

Yes. But also to do two other things...
1) Restore your memory
2) Assisting Iorveth in a noble ideal or travelling with him because he leaves for Aedirn first, that becomes helping out your friends Zoltan, Yarpen etc, as explained in dialogue.

This is explained in the cutscenes from prelude to war, and in dialogue with either Dethmold or Phillipa. Sabrina Glevissig cast it. Cedric prophesised that you would need to lift it to restore your memory.

beacuase he's not a dick...

He crosses the river to look for Triss as soon as you'd like him too, he crosses the river to look for the kingslayer as soon as he can. He doesn't want to abandon the river, he wants to lift the curse, it's what witchers do and it helps restore his memory. From there his goal becomes a pursuit of both in Loc Moine.

I really don't understand how this can even really seem like fetch quests to you. The only real fetch quest is the immortelle, and even then you have your dwarven friends to accompany you. The quests with royal blood, the dun banner, and Triss are very story heavy, let alone the succubus etc.

Chapter 1 was maybe a little more immersive I agree, but I just don't understand how you can not like Chapter 2.