mamashtakah – “..He told me it was OK to switch nusach, but not to switch pronunciation to Sfardit.His reasoning was that most people who do so end up pronouncing the words incorrectly.”
The Sephardim pronounce Hebrew correctly. Ashkenazim destroy the language, mostly by putting the emphasis on the wrong syllable. By doing this, they often change the meaning of the phrase. And before anyone jumps all over my comments, even the ‘holy’ Artscroll Siddurim have indicators of where to put the emphasis.