You may well be right from a legal point of view, although I did get my information from a solicitor posting on another forum. There are practical problems, however, one which you mentioned with HMRC, but perhaps a more immediate one in that if money is invested in shares on an brokers platform, I have found that they will only pay out money to a trustee account (ie an account in the name of the trust), and not to a personal account.
Geoff Parker