staywet,
I registered as soon as I started the CPL, and claimed for everything from 6 months before this. I can't remember all the details, and my AME wasn't VAT registered anyway.
You're complicating matters unnecessarily. The VAT man told you that you could claim for training if you intended to make vatable supplies afterwards. That's it. Why do you want to sell helicopter toys anyway? You're training to be a commercial pilot/instructor. The timescale is irrelevant. Occasionally people get asked for business plans, but the bottom line is that your VAT on training costs is recoverable, at least for the CPL. I'm not sure about the PPL, but why don't you phone the helpline again and ask. At the moment you're being far more devious than the VAT people are.