I just got a bit pissed off because of certain suggestions by OP :) However, I will still hold on to my point! I understand that your wife loves Sapkowski's novels and would really love to play the game. But, developers cannot/ can never ever have a target audience called "everyone" (I am not talking about age ratings here). The game already has an easy mode and I believe it is good enough, as it makes the combat really simple to play.

Seems to be an issue with the mouse. Pressing ENTER to reload the last save worked every time.

There's always a solution. When she gets frustrated during boss fights i take over finish the boss and she can play just for the story.

Nice :) that is definitely a great way to go at it! I kind of do the same thing when my wife gets stuck in Super Meat Boy!

I tried for over 3 hours last night and gave up-UGH!

Here's what I found out (after losing many, many, many times) When the games asks if you want to reload the last save game LEFT CLICK FIRST. Then you can click yes or no.

I, too, was getting what I thought were game crashes and I'd have to re-start but the left click worked for me.

Rocks are only thrown if you do NOT go immediately to the fallen pillar to deposit the bomb. Getting hit pretty much kills you. Or, you can stand behind the broken pillar base and time a run for the fallen portion. Once there, the rocks stop.
Actually, I found that I didn't have to restart the game. When the game hangs (and it still hangs in Act II), I CTRL-ALT-Del, pull up the task manager, and then click back on the game. It loads fine after that. I never actually end the task and restart the game. It could be that the temporary memory gets full and it just needs a refresh. FYI, this is a truly uneducated guess about the cause.

It took me a while to figure out how to beat this boss too, but I think it would have been a GREAT boss fight with just these changes:

1) At the very start I was moving my camera to face the boss and all of a sudden, BAM got hit by a tentacle taking most of my health. This only happened the first time, since afterwards I already knew what to expect, but it just seems like a cheap death. My camera should have already been focused on the monster instead of staring at Geralt's face (the opposite direction). Maybe it wasn't like this for everyone's game?

2) The middle tentacles should have weak spots too, because I didn't recognize right away that I couldn't destroy them. Kept trying to trap them and it was very frustrating. The battle should have involved you cutting off all the arms and then using a QTE to throw a bomb into its mouth, or something cool like that. Sure, less "whoa this looks so cool to watch" moments, but that's what movies are for. I never really feel badass watching Geralt do a QTE attack, but I feel badass when I have full control even if it looks less "epic".

3) The QTE at the end was way too vague. Took me a lot of running around and dying to thrown rocks and electric barriers before I realized that I had to run up the ramp.

I probably died about four times during this bossfight. No real issue, just learnt from past mistakes and adjusted my tactics accordingly. I did try to trap the middle tentacles, and promptly gave up after the second attempt as I had a feeling they were "untrappable". Hmm, must have been the big, glowing weak-points on the other tentacles >_>

Anyway, I really didn't find this boss hard at all. Nothing stuck out as 'bad design' during the entire fight. Perhaps I found it easier than you because of previous experience with similar games? If I recall correctly, someone suggested on this thread that "this game may not be for you" -- if you're having this much trouble with the Krayan, I'm inclined to agree.