J.D. A. answered 03/26/19
Genealogist & Historical Researcher
Hi. I'm a librarian at a Jewish history library. The short answers to your questions are:
Yes, you can absolutely move resh to /r/ if that is more comfortable ; in fact, some older dialectal pronunciations of Israeli Hebrew in colloquial and high-register (newscaster) speech use a trilled r.
The ayin question is more complicated.
In high-register and some of those same older dialectal phonetics, ayin may be voiced for purposes of:
- making a clear, enunciated distinction when necessary in selected words
- in literary or poetic speech
- in the colloquial accent of Hebrew speakers who have a family background coming from other languages where ayin is distinct
However, in typical Modern Hebrew it may be seen as excessive or unnecessary to make every ayin voiced. It basically is disappearing.