Hi, gosh, not to be negative, but you all generally make it worse. It seems that even though you all have a good grasp on English language, it is clear that you are mostly not English or American.
The term "afraid" can be looked at as "I realize" or "I suppose" Fear can, but does not necessarily have much to do with it. Furthermore, American English is often evolving unfortunately becoming more simplified thanks to black culture, I'm afraid. Perhaps the writer or speaker is trying to convey that they deem the outcome unfortunate. In other words, you wont say, "I'm afraid you made me happy" but you can say " The people are angry I'm afraid" The more proper way is to use it at the end of sentence to be less serious, or coy, sarcastic as well. Perhaps a way of saying not certain; to not commit fully to your statement, but the context must be taken into account. I am only on this blog because of a misunderstanding on Facebook with my woman friend from Hong Kong. The subject being "Cheating sexually", she wrote a little scenario. I was being cute to say..."it happens all the time, I'm afraid"
But she took it as to mean that i thought the subject matter was inappropriate for my facebook. That i was afraid! So, I'm sending a few links...amazing how much written on this expression. "afraid not" kind of an appologetic "no" or, saying it may be better if things were different. "Is it going to rain?" "I'm afraid not" that response would indicate that the person replying would rather have it rain, but not fearful of no rain. It is also a way of being rude in American style..."May I have a cigarette?" "I'm afraid not" that is a sarcastic and annoying way to look down upon someone while denying them something. Good question....as far as proper writing? go ahead and use it, writing is more art than formality. It is a good way to open discussion on a subject if you want the reader to inquire as to clarification as to why you are "afraid not"
Lastly, there is a funny joke about "a frayed Knot" but thats for another time...google it. thanks for reading