RE: ADSactly Education: Dealing with Accents in Language Teaching and Learning.
Right. You made some good points. Regarding rules, the phonetic palette of each language can be flexible enough to allow regional or even national variations of the same phoneme.
Take /ei/ for instance, produced in closters such as face or mate. The general rule may be to pronounce "a" as /ei/ when it precedes a consonant and a silent "e", and yet in some regions face is pronounced /fais/ and mate /mait/. However, those may be uncommon variations and learners should always aim at the "mainstream" variations.
Students in Latin America usually debate whether they should learn the British or the American pronunciation (usually implying that one is better than the other). One may be more "used" (as measured by number of speakers) than the other, but learners do not ned to get into the geopolitics of language. To be on the safe side, as long as they coherently adopt either accent (or at least the most distinctive features), they'll be fine (it would be otherwise weird to pronounce certain words a la americana and other a la britanica).
Fortunately, British and American Englishes are not too far from one another in terms of vocabulary or pronunciation. There is no risk of serious misunderstandings. It might be better to pick American if your goal is to become proficient at English. That's because some parts of colloquial British vocabulary tend to be not well-known to most people who speak English as a second language or even North Americans whereas the British usually have enough exposure to American English to know the American counterparts of those words.
Exactly. And even within the different registers of American English, there are regional variations that can challenge any other speaker's understanding, even native speakers of english, let alone L2 learners. But the beauty of linguistic interaction is that exposure and openmindedness can easily help overcome these communication hurdles.