Not sure what you mean by English culture, and whether that means the culture of England or of English speakers. Maybe you could provide more information as to exactly what you mean.
In the USA it is not illegal to say fuck in public, unless you are using language that is harassment, 'fighting words', trying to invite violence, etc. The Supreme Court ruled that the word fuck could be displayed on clothing in public property. This is true even in areas where children might see it. Once you take your child out of your home, you risk exposing them to culture at large.
On private property, corporations usually have codes of behavior and dress that employees are expected to adhere to. But pragmatically, unless one is, again, harassing or inciting, one is usually given the slack to use profanity at the work place, within reason. An employer could certainly insist that his employees not do so.
Children are attuned to what their parents, neighbors, and/or caregivers say, so one should monitor the language used around kids if you don't want the F-word passed onto them. Anyway they will probably hear it from some source other than you, say a neighbor or on YouTube before they are in school anyway. It does seem sensible to acknowledge that some words are usually not appropriate for children to use.
If you do not want to hear the F-word, you should avoid most R-rated movies (in USA), and avoid PG-13 movies if you want to avoid milder words, like damn and hell.
In the USA, these guidelines apply equally to men and women, and I've met many a cursing woman. It does still seem a bit unladylike and unseemly for a woman to habitually use profanity other than mild forms, and anyway research shows that males curse more.
People will have different opinions about rudeness. I think in some circumstances, the imperative mood can come across as rude, because it's a very direct way of asking someone to do something. It can make your question feel more like a demand than a request.
"Tell me" is a relatively direct way of asking a question, and adding "please" doesn't really soften this. As mentioned by the commenter, asking "Can you tell me" is less direct and therefore generally perceived as more polite. (There's a similar effect with "give me": "give me the answer" sounds rude, even if accompanied by "please," while "could you give me the answer" is not quite as bad).
The following strategies for avoiding the imperative mood are often used by native speakers, although not in all circumstances:
- using the word "could" or "can": "could you do this" rather than "do this"
- replacing an imperative with a conditional statement about yourself: "I would like to know" rather than "tell me," "I would like to have" rather than "give me."
Another reason, completely separate, why people might object is because, as MorganFR mentions, this isn't useful information at all (especially if you add it at the end of all of your questions). Especially on Stack Exchange, people often prefer questioners to be brief and to the point. Adding extraneous words may be perceived as rude, since it makes the question take longer to read and process. (Yes, I know this conflicts with what I said earlier about "can you tell me" being more polite than "tell me").
Best Answer
To answer your question, yes, that three-word phrase can be used as an exclamation, and I think it would generally be regarded as a compliment. However, a little more context would help to make your intentions clear.
Adding an adjective might be a good idea:
because without it, the phrase could also mean one of these:
As for it being "inappropriate," that depends on the situation. If I was looking at a coworker’s Facebook page, and she was posing rather flirtatiously, it might not be a good idea to say "What a pose!" in the workplace. But assuming you're not going to cross any boundaries of professionalism, there's nothing wrong with the remark.
In fact, the construct isn't all that not uncommon; we can use "What an X!" as a shortened way to express our approval about something. For example:
can mean, "What a great night we had last night," or, "What a dreadful night we had last night." (Context usually makes it clear. If I'm talking about an lovely evening of dancing, I'm saying it was great. If I'm talking about staying in the emergency room until 3AM because my daughter was injured, I'm talking about something different.) Similarly, I can say,
when I see a car driving down the street. If the car is a sleek Lamborghini, most would interpret my meaning to be, "What a sweet car!" If it's a jalopy, however, my meaning would be, "What a piece of junk!"