I am a LA and I have never heard of someone saying that a LA can change what a cust wants without speaking to her. I have cust mail me their quilts from all over the States,with notes of what they want. If it doesn't work I call them and we make a decision that works for the cust.
I use only good bat, Pellon or Quilters Dream,I carry both cotton and cotton/poly blend. If the cust wants a poly bat,I will do that. I change color of the threads all the time and it never throws my tension off.
It sound like you had a very lazy and selfish LA.
It is time for a change. Good Luck