Guild Wars 2

Are these used up during the demo?

The demo character slots are a copy from your account. Nothing there affects your “real” account.

I just checked exactly this – I had 128 transmutation charges, used 8 changing my beta characters equipment, logged into a different character and I still had 128.

I assume exactly the same applies to everything else on your account. That’s certainly the way it worked during the HoT beta – you could spend all your gold, delete everything out your bank, switch characters and it was all back. (Just make sure you’re on the beta character when you use stuff you want to save!)

On the other hand if you get a precursor on your beta character there is no way to give it to anyone else.