Sweet Max, fret not, my friend, fret not. I doubt there is anyone who has perfect pronunciation. And who's to say what that is, anyway? Each country, even, has regional variations, let alone the differences between countries.
And not just vowels, either-rrrr, hee-yah? In Kentucky, you can hear something like this: Lemme borry yer pin to wraht with.

Singing pronunciation does or should differ, though, I think. Bob? AnnaS.? Faldage? Have other singers been taught this? As an example, in choir I sing ow-er, not are,
for the word our. 'Are' is very commonly heard here for
'our', and sounds even worse sung than it does spoken.