Some games simply don't allow skipping of cutscenes. Once you finish a game, some then allow you to. Others don't. Not sure about FC3 though.
I would not worry about it though - it's not like some of these 'movie games' that are more cutscene than gameplay.
Knowing you Daniel, I can guarantee that there will be parts of the game you'll love, parts you'll like but wish were different and some parts you'll hate.
You'll like the fact that it has re-mappable buttons at least
The core gameplay is not that dissimilar to FC2. Go to point A then go to point B and so on.
However, what made that a huge chore in FC2 is no longer a huge chore in FC3 thanks to a lot more fast travel locations you can use from anywhere. (No more traveling to stupid bus stops etc)
To help break the monotony, there are now more side 'quest' distractions like hunting animals to craft better pouches to raise carrying capacities. Instead of looking for gemstones, you now look for memory cards, Relics and letters. 'Busy work' shit like this helps 'flesh out' the exploration side of things.
Vehicle handling is the same as FC2. Same are the guns that not only look and sound good, they feel good to use. (I also have the buttkicker on and you can really feel each shot. (This buttkicker is f*cking awesome

) Although sniper and assault weapons seem to be immune to 'bullet drop off'. The bow isn't thankfully. It depends on how you like your trajectory in games. Real or 'accessible'.
With your specs, you should be able to find a happy enough medium between IQ and performance. It scales well in the looks department.
Hopefully by now you know that despite my being a lot more tolerant to certain aspects of gameplay you don't like (un-mappable buttons, complex menus, storylines etc) you know how unbiased my game opinions are.
The game is not perfect. None are. But to me FC3 is what FC2
should've been.
****
On a side note, I've been trying the different AO methods and I personally think that HDAO has a minor edge over HBAO in the looks department. A smidge more natural and tad less glitchy than HBAO. However I am playing on a 40" LCD TV, so that may have an impact on how it looks to me vs a monitor.
(I've read people claiming that nvidia can sometimes look more 'cartoon-ish' than AMD. FC3 seems to be a good example of that claim.)
I reckon try it for yourselves. It's subjective. With SLI enabled, luckily I can absorb the FPS hit of HDAO on Nvidia. And just to see the hit, I'm running x32 CSAA. Surprisingly, it's still very smooth. The adaptive vsync appears that it's doing what it's supposed to - keep the frames as even as possible.