How old is he?
Moving things around could upset him, but it could also be hormonal, as this is spring-time (depending on his age and how long you have had him).
I disagree with your trainer...who was this trainer?...
How long have you had your bird?
Can you give me a time-line?
For example- "Got him at 6 months and he was great until around 1 year, when he started biting. I have had him for a year and a half, but he is 2, so he has been biting for a year " (or something like that)
How were you touching him before this all started? Any pets outside of the head and neck? No huts or shadowy spaces (you already said, so that is good).
What are you doing when you get bitten? If you can't think of specifics, can you tell me whether you were looking at your bird or attempting to interact, or whether your bird came after you while you were in the room but looking at the computer, TV, book, game or something besides your bird?
Is it just you in the room, or are there animals or other people around?
When you are bitten, does the bird come to you, or is it when you are trying to touch the bird?
Is your hand outside or inside of the cage on most occurrences?
Are you trying to take your bird out or put him/her back when it happens?
Is there a time of day when it happens more?
What is your schedule and how long is he out daily?
Does he ever leave your room? *This is also an important question* considering his apparent upset at you moving things.
On top of everything else, parrots often push away at sexual maturity. You kind of have to re-build trust if that is the issue. Make sure you are reading his body language. If you are getting bitten often, it means that you are missing signals and triggers (because biting like this does not occur in the wild except in a very last resort). Shoot for 10-12 hours sleep nightly (10 is okay too, but no lower--- if 12 is too much, you could try 11 or 10.) Keep avoiding access to huts/tents/shadowy spaces....
Let me know on the rest and I'll try to help if I can think of anything.