Yes proper placement in the arrangement of multiple instruments is so important, and proper dynamics in volume of sound. Timeline in putting together the show such an excellent idea! Example in wring for flutes, write different part for the first and second flutes, etc. Writing a sketch on the piano first, great idea! Having a plan where all the instruments will be placed for maximum impact. Yes music theory knowledge is so important. Yes, studying scores is good to learn about composition. Opera music is exciting to listen to, and must be very demanding of the composer as with opera so many voices, complex parts for orchestra, staging has to be worked into composition ideas, the acting and it goes on and on with Opera. Such wonderful constructive ideas contained in this video. Thank you so much!