There is a lot about pronouncing things correctly so we don't say the wrong thing, especially in tefilla. Eg in shema: we are to pronounce the ayin in "שמע" so it doesn't sound like "שמא"; "maybe", chas veshalom.
I have a two fold question. There are words that are homophones, and this can lead to unwanted meaning (eg כי יערב לו ידידותך), but we can't do anything about it. This actually applies to Ashkenazim with Shema as they generally pronounce ayin the same as aleph.
- So what are we to do?
- If nothing, then why are we so concerned about the ayin in shema?
This fear that we will end up saying something heretical - what is it based on? Surely the only fear about the ayin is from the general halacha of pronouncing the words of tefilla properly. We say many tefillot that are, in their homophonic meaning, heretical, and we don't have any issue with that (or do we?).