That's is an awfully good candidate! Hard indeed methinks to top the annoyance factor of that. :thumbsup:
Turn back you can't go this way (paraphrased) is annoying but can be eliminated via ini.
You cannot sleep in an owned bed / while trespassing is pretty annoying for me also.
Yeah second most annoying message for me would be a tie between you cannot wait while trespassing and you can't rest or fast travel with enemies nearby, lol. I usually don't even wanna wait, just wanna check the time really quick.
I downloaded a mod that made the mudcrabs passive. I found it ridiculous how far they can scan you, like when you're on the imperial city bridge, and they're like 20 feet below you. Yet, somehow, they know you're above them. And for godsakes, why did they make deer your enemies? They're like the most harmless creatures in the game. Now if there was only a mod that changed that.
And those skill pop ups are too far in between to annoy me. Just thank god they're not frequent, but I do find them a pleasant surprise when they pop up.