Authors experienced in orchestral music, your critisism and advices is needed.

Hi people, I’ve started to study the libraries’ orchestral sound. Please check some my first tries (they are short) and point me my mistakes, which things I need to put more attention on to improve.

And some more question:
Where is the threshold to stop endless efforts to nearing the sound to get realistic? In other words, does the piece need to sound like “live” orchestra recording or to give the “whole” feeling of orchestra energy is more important in stock music? Thanks in advance.