Hi Gina and thank you for your answer !
I guess the pronunciation is my biggest problem indeed, so I definitely take in consideration the comment you make ! As I am French, it's really nice to get opinion from native-English people as in France, nobody would really help me find the correct pronunciation... ^^
I am working with Jame Vendera's "Raise your voice" and even if I got some classical lessons some years ago, I am learning almost everything in that book.
I will try to use your tips for the next songs I record, thank you :)