"Are you a good swimmer" and "do you swim well" both mean the same thing and sound fine to me, though the first one is maybe a bit more natural. The difference between these and your questions about driving and singing is that you are asking how good the person is at swimming as opposed to if the person has the ability to swim. The question "Are you a swimmer?" also makes me think you are asking about a job (or something similar). Specifically for your questions: 1. "Are you a driver?" makes me think you are asking about a job. "Can you drive?" is probably the best way to ask if the person has the ability to drive. If you are more interested in how well the person drives, you can also ask "Are you a good driver?" If the person can't drive at all, then the response should be "no" for both questions. 2. "Are you a singer?" makes me think you are asking about a job. The following do not make me think so: "Are you a good singer?", "Are you much of a singer?", "Do you sing?", "Do you sing well?"

Do you know what "small yellow men" is？

You may have already got found out the answer when you clicked in and saw this picture.
Yes, the "small yellow men" refers to the Minions.
(ฅ>ω<*ฅ)
Chinese translated  "Minions"  has been translated into Chinese as "小黄人", which means "small yellow men" in English.
The Chinese name is a vivid description to of the appearance of the Minions. "小黄人" should be a good translation to satisfy the target readers (maybe "audience" instead of "readers") because it does impress Chinese people. However, it's not a good translation to establish the communication between different cultures, as foreigners may fail to match "small yellow men" with "Minions" without hints.
I have something that I have personally experienced to share with you.
Last year, I went to the Universal Studios Japan and was attracted by the King Bob popcorn bucket there.
The popcorn bucket designed as shaped like or design with depending on what you mean King Bob was so lovely that I immediately decided to buy it at the first sight.
"I want a… a small yellow man." I faltered when standing in front of the stall, until when I realized that I didn't know how to say "小黄人" in English.
"Small yellow man？" , the staff member repeated with confusion. Apparently, she couldn't understand me. Another staff member laughed and said, "It's Minion. Chinese all say like that." Note: this should really be "say it like that," but since it's a quote of what someone else said, I am leaving it as-is. (How embarrassed I was.ಥ_ಥ)
Chinese characters are a form of ideogram, so . So it's a common occurrence that the foreign words lose their original pronunciations and change both their forms and meanings in the process of entering China. It's an interesting contrast that Japanese, though also belonging to the  an eastern Asian language, contains a large amount of loanwords that keep their original pronunciations. It's really ファンタスティック(fantastic). ：)

——我——是——1——条——快——乐——的——分——割——线——
This is my second composition on italki. Please kindly help me polish it.
Welcome for any corrections and comments.
(｡･ω･｡)ﾉ♡