Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.

I am looking for the term describing when your hair grows kind of in a circular direction (defined by the direction of your hair root). Many people have something like this on the back of their heads or even on their foreheads. I found the term hair crown on dict.cc but I feel like this is either not the correct term for it or it is not very widely used. There is a German article on human hair including a section about these things but I could not find the English equivalent. In German, these are called Haarwirbel meaning something like hair whirl.
You probably want to use hair whorl. You'll notice that it's virtually the same as the German term, except with the alternate spelling of whorl/whirl. In English, whirl is the verb form, whorl is the noun.

Does this Bible verse have the same unfortunate double meaning in American English as it does in British English? The photo is taken from the 1984 translation of the (US) NIV. It looks as though the UK edition of the 1984 NIV had the same text; but in the 2011 update, the UK edition has ill in place of sick, while the US edition remains unchanged. I have visions of people bringing little pots of vomit...
The referent is just elided here. You can read this as meaning 'sick [friends]' or 'sick [relatives].' The reason it sounds odd to British ears is that the current British colloquial usage of 'sick' as a euphemism for 'vomit' is overpowering any other interpretation for you. Since that colloquial usage is relatively unheard of in America, you are correct that the phrase sounds less odd to American ears. Perhaps that did influence the translation choices made by the NIV.

I was wondering what 'take a stab at doing something' means? For example I'll take a stab at answering these.

As everybody has said, to take a stab at means to attempt. I want to additionally note here that I believe it to be related to the idiom stab in the dark, meaning an attempt at something with little guidance or hope of success. It doesn't carry the full weight of that meaning, though, just an attenuated implication of not necessarily knowing what one is doing, more likely used as mild self-deprecating humor than anything else.