Or any of his "minions". They geht highlighted but I can click as often as I want, nothing happens. 

The bugs are seriously getting more and more ridiculous and I'm fed up.

I get this bug often and it seems to happen randomly after some time playing. A solution seems to be going back to the main menu or just restart the game before reloading your save.

Thanks a lot and sorry for my impatience. Restarting the whole game solved it.

But I stumble upon bugs everyday, so I get frustrated easily, recently...

Yeah, same here. I put the game on hold for the time being, having to pay constant attention to the bugs that could break your save it's not what i had in mind when i bought the game. Oh well, hopefully we'll get a stable version soon...