Yeah I meant the output_log.txt file.. Sorry
Just to be sure we've been through these options:
Have you tried running Friar's Keep over again up to that save, and to the pillow/broom? (That is, from the previous save, which should be right after the FK's intro cinematic)
I noticed in the log you'd tried loading the savegame just before the pillow room (after Arn Stont decision point). Not that I really think it matters, but it's worth testing.
If this approach yields no results, I'd try jumping backwards step-by-step to see if it might be related to a savegame in your specific playthrough, or maybe try starting a new playthrough. That's pretty much a long shot, but might be worth a try if you're willing.
I decided to cave and uninstall/re-install entirely. Backed up my saves and verified the cache integrity, as per everyone's suggestions. But, it still looks like Kian isn't in the business of grabbing pillows.
As for my info, I'm using Windows 8.1, and I've downloaded the game through Steam. I'm using a trackpad (I have tried an external mouse, though, it doesn't seem to help). I just bought the game a few days ago, so I'm assuming patch 1.1.3? I'm not sure.
I also wanted to make sure you've run the Cache Integrity verification without re-installing. From what you wrote, it looks like you re-installed first, then did the verification. The verification runs through your currently installed files to check them for errors, so a re-install first and then a verification might not yield any results at all, as the files are just recently installed. I should have been a bit more specific about this before, but I'd try to run the verification tool again, just to make sure. However, it might not make a difference at all..
Other than that I cannot see any obvious errors within the log or anything that strikes me as odd behavior. The only thing is that I don't see anything about trying to pick up the pillow, but that's the problem here of course..
The fact that you can pick up other items than the pillow initially led me to believe there was something wrong with the files referring to the pillow of some sort, as it is an issue specifically for this item. But if the Cache Integrity verification tool doesn't report any errors, I'm currently at a loss to what more to do at this point other than trying to click it from every different angle (you can get up on the bed too). But I'm sure this is something you've tried in a lot of different ways.
I'm sorry I cannot give you anything more definite at this point, but please report back to me if anything should yield any results.