I’m guessing that no one has uncovered any statutory proscriptions on extraordinary pronunciation variations as the one mentioned in the thread title.
That’s Woolfardisworthy, and it’s pronounced “Woolsery”. Unless you meant the other Woolfardisworthy, which is also in Devon but near Crediton, which is pronmounced as it’s spelt.
There’s also an Alfardisworthy, but nobody’s ever been there because they can’t work out how to pronounce it to ask for directions.
As to the OP: no 
… I don’t really see how you could legislate. I mean, where do you draw the line between an “acceptable” pronunciation and an unacceptable one? Obviously not all names are spelt entirely phonetically, and a given spelling could have many valid pronunciations. Often, people won’t even agree on how a name is said. How could you create laws to regulate this?
For instance, I grew up near a village called Finchampstead. As a kid I always thought it was pronounced “Finch-hamp-sted”. I later discovered that the real locals pronounce it “Finch’m’stid”. Would both pronunciations have to be “accepted” legally? What about people called Ralph, etc.
Yes, and most of those newscasters didn’t grow up in the Cleveland area. Whenever my dad (who was born in 1934 and has lived in Cuyahoga County his whole life) hears an anchorman or weathercaster say “Kie-a-HOE-guh”, Dad immediately says something like: “He must not be from around here!” However, he’s now heard enough locals use the “incorrect” pronunciation that he figures the TV and radio stations must have all adopted it as a matter of style. Still, I’ll always say “Kie-a-HAWG-uh” unless I’m directly quoting someone who thinks the word rhymes with “buy a toga” or whatever.
I knew someone whose background was Greek and whose last name was Vilenica. The family pronounced it as if it was spelled Valencia and uttered by a “regular American” (i.e. one who doesn’t speak Spanish and say something on the oder of “bah-LENTH-ee-ah”).
I also had a classmate called Steve Buechele, who pronounced his surname “BEEK-ly”. Then a baseball player with the same name showed up in the big leagues, but went by “Boo-SHELL”. Maybe it’s an Alsatian name, since Alsace has been kicked back and forth between German-speakers and Francophones for years…
Finally, the alumni director at my alma mater was named Jesse Fanshaw. Obviously his branch of the family decided somewhere along the line that the Featherstonehaugh moniker was more trouble than it was worth!
I know Keighley is Keith-ley.I think Slaithwaite is something like Sla-waite or Slah-waite.
Try Cirencester then 
Yeah, I locked my keys in my car there once, and the lady I called at AAA insisted there was no such place as San Rafael, and I must be completely lost. “In fact,” she politely suggested, “are you sure you’re really near San Francisco?” I said, “yeah, I’m pretty sure that was the Golden Gate Bridge I crossed about 10 minutes ago.” Finally she realized “oh, I bet you’re in San Ruhfell!”
So, either way, when speaking carefully, you still have four syllables, right?
I had a teacher called Ruetschle – “Ritchley” – about as close as a Midwesterner could get to the actual German pronunciation, I suppose.
I had a classmate called Fuchs. That’s “Fyushs” [fjuSs] not “Fooks.” I don’t know about you, but to me, “Fyushs” is not easy to say.
I believe “Fanshaw” and “Fanshawe” are not unknown in England.
Surely the pronunciation depends on what your language is.The same thing can be pronounced different ways…
Consider the letter V.Go on,consider it.Hard.
To a Welshman,it would be a F sound,to an Englishman V,to a Spaniard a B sound, to a Roman a W sound and to a Middle Ages English speaker a kind of U sound.
With all the names quoted,those who know the pronunciation know that it’s right.
To those who don’t it looks nothing like what it should sound like.
The best I can think of is a 14-letter-word that sounds nothing like what it looks like and is pronounced in just two syllables
halfpennyworth…pronounced apeth or hapeth
Heh. You can always tell when the TV announcer is not from SK. Let’s not even get started on the pronunciation of Regina.
My hometown is Saskatoon, but I’m living in St. Louis, MO, right now. Possibly because there is also a St. Louis, SK, friends at home are always asking how things are in Saint Looee. I sometimes wonder if they are trying to proclaim their Canadian superiority by saying “Louis” as it would be in French – but really, folks, if you’re gonna say it that way, at least try for a French “Saint”. That is all.
Oh, and LSLGuy mentioned St Louis street names. My favorite mangling after De Baliviere is Pernod.
Then, there is Montpellier, Vermont…
That might be the wrong way round - I don’t think the Welsh alphabet has the letter “V”, but the letter "“F” sounds like “V” (with “FF " sounding like"F” in English)
In German, on the other hand, “V” is indeed “F”.
Or Jimenez with a hard J as in jam.
How would Englishpeople pronounce “Middlesex”? Mid-sex? Mid-six?
Is “Westminster” short for anything? (For the longest time I thought it was “Westminister” before realizing there should be only one “i.”)
WRS
I’d say those are still kind of up in the air. I routinely heard bus drivers pronounce the street names as per Spanish when I lived there. Well, not Manchaca… never rode over there. That Anglicization doesn’t make much sense anyway… is it supposed to rhyme with Mopac or something? Anyway most people I know pronounce Guadalupe the Spanish way, although not San Jacinto or Rio Grande. Don’t forget Koenig and Burnet. Never did figure out the proper way to say Whitis Avenue.
Voyvodich could easily be Croatian or Serbian surname. In Croatia and Serbia there is NO WAY to pronounce it differently than VOY-VO-DICH. Serbian and Croatian languages are fully phonetic - one letter stands for one sound. Amen. The rules are very simple - and no “creative interpretations” are allowed.
Alas, no National Spelling Bee competitions 
Middlesex is pronounced as it is spelt, with the accent on the first syllable.
Westminster is not short for anything; it comes from “west” and “minster”, meaning monastery or church – it’s the site of the “minster” at the western edge of the city of London.
Not up here around Monterey. We do not call the Salinas Rodeo the roh-dee-oh, we pronounce it a lot closer to Spanish roh-deh-oh.
I’ve never heard San Francisco, San Jose, Santa Clara, Santa Cruz, Sacramento, Vallejo pronounced like that. Everyone I know, Bay Area Natives or not pronounce them as:
san fran-sis-ko
san ho-zeh
san-tuh clare-uh
san-tuh crooz
sa-cruh-men-toh
vuh-leh-ho
Humorously, we call Vallejo - Valley Jo (and I’ve heard this from people who live there)
My mother’s uncles from Kansas came one year and asked her “Where’s San Josie?”. Due to influence of Salina in Kansas, they pronounced Salinas as “Suh-linus”
Fortunately, most of the cities here are straightforward (Marina, Castroville, Seaside, Sand City, Watsonville), but i’ve heard people goof up Pajaro - puh-jah-ro (where we say pah-hah-ro, closer to Spanish).
Other towns and places that give problems:
Paicines - Pai-see-nez (sometimes said as pai-seenz by non locals)
Jolon - ho-lohn (jah-luh by non locals)
Panoche - pah-noh-cheh (puh-noh-chee by non locals)
Quien Sabe (a canyon) - Kee-en Sah-beh (and i’ve heard this one said as kwee-en sehb)
I suspect if I and some other Bay Area Dopers were to converse we wouldn’t disagree much on pronunciation. It’s just this little problem of English letters being too imprecise to render sounds accurately.
For example, if I say “SAN frun-SIS-co”, but Doobieous says “san fran-sis-ko”, I don’t think they’re really that different, if they even are different. I don’t shout the first and third syllables and mumble the others, and I’m sure Doobieous doesn’t say them all in a flat, robotic monotone with no emphasis anywhere. Also, the vowel sounds in the first and second syllables are similar but not identical. The “a” in “San” is a short “a”, but the “a” in “Fran” is what you might call a supershort “a”, at least the way people I know pronounce it. To me it sort of sounds partway between a short “a” and a short “u”.
THis is why anyone who posts to these posts really should learn ASCII IPA transcription.
Here’s how I hear the various cities pronounced:
San Francisco /s&n fr&n’sIsko:/
San Jose /s&n ho’zEj/
San Rafael /s&n rV’fEl/
San Ramon /s&n rVmo:n/
Santa Clara /'s&nt@ 'klEr@/
Santa Cruz /'s&nt@ 'kru:z/
Sacramento /s&krV’mEnto:/
Vallejo /vV’lEjho:/
San Mateo /s&n mVtEjo:/
San Leandro /s&n lij&ndro:/
Los Gatos /lAs 'g&to:s/
Antioch /&ntijAk/
Berkeley /b@rklij:/
Syncope.