This is 17th century English, a time when spelling was slightly different and, above all, less standardized than today. "Transcribed" in modern English you'd get:
"a proud and very profane young man."
The definition of "pussy" in the two dictionary references you cited as meaning "[having] sex with a woman" are both mistaken, in my opinion, at least in common American English usage. I suspect Babylon borrowed the "unusual definition" from the Cambridge dictionary without doing a reality check to see if it was accurate. The word is used in phrases that mean having sex with a woman, but in itself, it simply refers to female genitals.
"Pussy" is not necessarily an offensive word, although calling someone "a pussy" certainly is. The late actor Robin Williams, while being interviewed by James Lipton on the television program, Inside the Actors Studio, was asked the standard question, "What's your favorite curse word?" To which Williams replied, "It's my favorite because I'm a big fan: Pussy." He then repeated it numerous times, savoring its implications with each utterance to the great delight and embarrassment of Lipton and the audience.
In contrast, Lipton asked Williams, "What's your least favorite word?"
Robin Williams replied, "Cunt. Least favorite word because it's so negative. It's the one word that'll get me kicked out of the house." Unlike "pussy," "cunt" is always considered offensive, even though it effectively means the same thing (although with a decidedly negative connotation).
For more comments from the Lipton interview, see: http://www.imdb.com/title/tt0611309/quotes
While some might think that Robin Williams was no authority on the English language, I would argue that he understood the meanings, nuances and usage of English better than most of us. I also believe it is important for English learners to know the meanings of English slang, even (perhaps especially) if they are considered vulgar and/or offensive.
Best Answer
“Very talented and prolific singer” is a perfectly normal use of the word prolific. It means a singer who wrote or performed a lot of songs (prolific) and who did that well (talented).
Prolific alone is only an indication of quantity, not quality, even though prolific tends to be slightly laudative. You can say that someone is a “prolific but mediocre singer”.
Note that prolific generally means “which produces a large amount” or “which gives a large amount”, not “which contains a large amount”.