Two thoughts/words of advice:
1. Don't forget you are a paying customer... or another way to say it... don't pay to be angry.
I've know parents who were so frustrated with the team, coach, something... yet paid over two grand annually to be there.
2. Find a realistic friend. Find someone who seems to understand soccer but also wants the best for kids... then let that person be able to speak realism back into you. I get emotionally up or down with stuff... and have a friend who is like, "don't be dumb."
Regarding, positions... I'd usually lean towards by U15/U16 need to have an idea of offensive role and interior v exterior. The differences between a CB and an outside back can be significant. Also, the difference between playing on the back line, midfield or front line can also be significant.
So, I wouldn't worry about a U16 switching between 8 and 10 or outside back and center back... but I'd lean away from seeing them switch from 9 to outside back.