Can there be a guide to what interruptions and skips can be made during parts of davening? I'd like to see such a guide and think it would be extremely helpful to the users of Mi Yodeya.
There is an English sefer Priority in Prayer which is a quality and easy to use sefer for these issues. If I remember correctly its Hebrew title is Avnei Yoshfei.
There is a book Shegiyot mi-Yavin which is dedicated to helping with various mistakes in prayers and brachos.