"Wherefore art thou" means "Why are you". When Juliet asks "Wherefore art thou Romeo" she's lamenting that the guy she just fell for was Romeo. It's kind of like "Why did it have to be Romeo".

Not sure about "been there". Hath and hast were commonly as helping verbs the way that have and had are used today. I think "to have" verbs were still used for perfect tenses. 80% of the words used in Early Modern English are still in use today, so it's perfectly comprehensible for most modern readers. Chaucer's Middle English and Beade's Old English "Anglo-Saxon" pose a bigger problem.

I don't actually know about it like Crazy but based on his translation of the first half I'd guess that "been there" means something along the lines of "there" or, based on the context, "have been there." That would make it a sort of "Why have you been there" or "Why are you being (sitting, standing, existing) there (in that spot)". I don't know just my conjectures. Curious though, why are you asking?

"Why have you been there?" is what the sentence translates as. Many verbs were conjugated in the perfect tenses in EME, including come, become (I AM become death), rise, and fall. I was wondering if this applied to the verb to be because it occurred to me as being possible. The same is still done in German today "Warum BIST du dort gewesen" rather than Warum HAST du dort gewesen.

bump

I googled the phrase ["art been" or "hast been"] and turned up a lot of results for "hast been" (as in, have been), and maybe one result on the first three pages for "art been" where "art" was being used in the sense of "are" and not "artwork" or one of the other meanings of the contemporary English word "art."
Having no expertise, I would guess from that that "hast been" is correct, and "art been," if not incorrect, was at least rather unusual.

"Welcome back! Wherefore art thou been, Giulietta?"
http://www.motoring.co.za/index.php?fSectionId=4247&fArticleId=5369321
Ask Alfa. They appear to know.

No. It's still English. "Why are you been there?" doesn't make any sense. You could say, "wherefore art thou there?" I think that's odd, but grammatical.

I think it probably didn't matter a f*ck at that time whether your grammar was perfect or not, since there were no set-down rules. Communication may have been higher on the agenda. Think on . . .